FINALLY: To loipon: (Phil 4:8; 2Cor 13:11; Ep 6:10; 1Thes 4:1; 1Pe 3:8)

Finally (3062) (loipon from loipós = remaining) pertains to the part of a whole which remains or continues  and thus constitutes the rest of the whole. Literally this phrase is as for the rest and in every case, the use of this Greek expression has the idea of something left over (furthermore, so then, now then would be synonyms). Clearly Paul does not mean by this that he is about to close his letter for half of the letter is still to come!

In English when we hear the preacher say "finally", we know the sermon coming to an end soon. But that is not the way Paul uses finally in his letters for he frequently uses loipon frequently in the concluding portion of his Epistles (cp, Ephesians 6:10 [note], 1Thessalonians 4:1 [note], 2 Cor 13:11, 2 Thes 3:1) often introducing  practical exhortations but not necessarily implying that the epistle is drawing to a close. In other words, he uses loipon to mark a transition in the subject being discussed. In fact, there is another "finally" in Philippians 4:8 (note).

As Wuest explains...

Paul has been concerned so far in the letter with the internal dissensions, mild though they were, that endangered the well-being of the Philippian church. Now he turns his attention to a danger that would assail it from without, namely, the Judaizers. These were Jews who were nominal Christians, who accepted the Lord Jesus as the Saviour of Israel only, and who taught that a Gentile had to come through the gate of Judaism in order to be saved. They thus refused to accept the fact of the setting aside of Israel at the Cross, and the bringing in of the Church at Pentecost. They wished to continue under the Mosaic law. What happened in the Galatian churches, Paul was trying to forestall in the church at Philippi. (Wuest, K. S. Wuest's Word Studies from the Greek New Testament: Eerdmans or Logos)

MY BRETHREN REJOICE IN THE LORD: adelphoi mou, chairete (2PPAM) en kurio: (Phil 3:3; 4:4; Dt 12:18; 16:11; 1Sa 2:1; 1 Ch 15:28; 16:10,31-33; 29:22; 2Ch 30:26,27; Neh 8:10; Job 22:26; Ps 5:11; 32:11; 33:1; 37:4; 42:4; Ps 97:1; 100:1,2; 149:2; Isa 12:2,3; 41:16; 61:10; 65:14; 66:11,12; Joel 2:23; Hab 3:17,18; Zeph 3:14,17; Zech 10:7; Mt 5:12; Lu 1:47; Ro 5:2,3,11; 1Th 5:16; Js 1:2; 1Pe 1:6-8; 4:13)

Spurgeon comments...

Let this be the end of everything; before you get to the end of it, and when you do get to the end of it, “rejoice in the Lord.” It is incumbent upon us, as Christians, to rise out of our despondencies. Joy should be the normal state of the Christian. What a happy religion is ours in which it is a duty to be happy! “Finally, my brethren, rejoice in the Lord.”

It is your privilege, it is your duty, to rejoice in God; — not in your health, your wealth, your children, your prosperity, but in the Lord.” There is the unchanging and unbounded source of joy. It will do you no harm to rejoice in the Lord; the more you rejoice in Him, the more spiritually-minded will you become. “Finally, my brethren.” That is, even to the end, not with you the bitter end; but even to the end of life, rejoice in the Lord. Make this the finis of everything, the end of every day, the end of every year, the end of life. “Finally, my brethren, rejoice in the Lord.” Blessed is that religion in which it is a duty to be happy.

Rejoice in the Lord - He could have said simply "Rejoice" but connects rejoicing with the Person of Christ. Christians can rejoice because of their relationship. They exist in the sphere of an intimate union with the risen Christ and thus are enabled to rejoice as they abide in Christ Jesus, the Vine.

Eadie adds that...

The modifying phrase in the Lord does not mean, “on account of Christ,” or as becomes Christians, but it defines the sphere and character of the joy. (See notes Romans 14:17; 1Thessalonians 1:6; ; Galatians 5:22; Colossians 1:11) The Christian religion is no morose system, stifling every spring of cheerfulness in the heart, or converting its waters into those of Marah (bitterness). It lifts the spirit out of the thrall (a state of being totally subject to some need, desire, appetite, etc) and misery of sin, and elevates it to the enjoyment of the divine favour, and the possession of the divine image; nay, there is a luxury in that sorrow which weeps tears of genuine contrition.

Therefore, to mope and mourn, to put on sackcloth and cleave to the dust, is not the part of those who are in the Lord, the exalted Saviour, Who guarantees them “pleasures for evermore.” Such joy is not more remote from a gloomy and morbid melancholy, on the one hand, than it is, on the other hand, from the delirious ecstasies of fanaticism, or the inner trances and raptures of mystic Quietism.

Chrysostom remarks that this joy is not “according to the world,” and his idea, according to his view of the connection, is, that these tribulations or sorrows referred to, being according to Christ, bring joy. This last opinion, however, is not from the context, though certainly the first remark is correct, for the joy of the world is often as transient as the crackling of thorns under a pot; and it often resembles the cup which, as it sparkles, tempts to the final exhaustion of its bitter dregs. The express definition or limitation in the Lord may be meant to show, that beyond the Lord this joy is weakened, or has no place; and that, if the Lord Alone is to be rejoiced in, the Lord Alone must be trusted in. The sentiment thus warned and fortified them against the Judaizers, whose opinions, in proportion as they tended to lead away from the Lord, must have retarded all joy in Him; while, if the Philippian believers continued to rejoice in the Lord, that emotion, from its source and nature, guarded them against such delusions. The next clause has seemed to many to be an abrupt transition. (Epistle of St. Paul to the Philippians - 387 page book in Pdf)

Brethren (80) (adelphos from a = denoting unity + delphús = womb = born from same womb) is literally of the same womb and speaks of a fellowship of lives based on identity of origin.

As Eadie remarks...

The apostle addresses the Philippian converts, “as my brethren”. There was no official hauteur with him, no such assumption of superiority as would place him in a higher or more select brotherhood than that which belonged to all the churches. (Epistle of St. Paul to the Philippians - 387 page book in Pdf)

Spurgeon writes that...

“Finally, my brethren, rejoice in the Lord.” But never do it finally, never come to an end of it. Rejoice in the Lord, and yet again rejoice, and yet again rejoice; and as long as you live, rejoice in the Lord.

Rejoice (5463) (chairo) to be glad or delighted, to celebrate, to be cheerful. Joy is a feeling of inner gladness, delight or rejoicing. Joy for the Christian is marked by celebration and expectation of God’s ultimate victory over the powers of sin and darkness. We should make a clear distinction between joy and happiness, which is word related to "happenstance" which defines that exhilarating feeling we all have when things go well and circumstances are agreeable. The believer's joy however is not contingent upon circumstances but upon relationship. As we abide in the Vine, walk in the power of the Spirit of Christ, under His control, we find that our joy persists in adverse circumstances for it independent of those circumstances. Furthermore, the believer's rejoicing is not a natural emotional response as we experience when we are "happy", but a supernatural response because of our spiritual union with Christ and the indwelling of the Holy Spirit. It is a response based upon truth,  including truths such as the sovereignty of God, an assurance that He is in control, a truth which comes from the Scriptures (which is another reason we need to daily "eat" the bread of life, that we might be spiritually nourished and strengthened in our inner man). Joy is the outflow of faith and faith comes from hearing and hearing by the Word of Christ (see note Romans 10:17). 

An anonymous psalmist illustrates this relationship between rejoicing and a knowledge of the Word of truth writing...

our heart rejoices in Him, because we trust in His holy Name. (Psalm 33:21) (See studies on Names of the LORD as a Strong Tower - because to trust this Name we must know this Name in its manifold glory and we will have a foundation for rejoicing without ceasing.)

Spurgeon writes...

We, who trust, cannot but be of a glad heart, our inmost nature must triumph in our faithful God. Because we have trusted in his holy Name. The root of faith in due time bears the flower of rejoicing. Doubts breed sorrow, confidence creates joy.

In a similar manner David confidently declares...

Thou wilt make known to me the path of life; In Thy presence is fulness of joy; In Thy right hand there are pleasures forever. (Psalm 16:11)

Spurgeon comments on fulness of joy writing...

Christ being raised from the dead ascended into glory, to dwell in constant nearness to God, where joy is at its full for ever: the foresight of this urged Him onward in His glorious but grievous toil (see note Hebrews 12:2). To bring His chosen to eternal happiness was the high ambition which inspired Him, and made Him wade through a sea of blood. O God, when a worldling's mirth (gladness or gaiety as shown by or accompanied with laughter) has all expired, for ever with Jesus may we dwell at Thy right hand, where there are pleasures for evermore; and meanwhile, may we have an earnest (down payment) by tasting thy love below. Trapp's note on the heavenly verse which closes the Psalm is a sweet morsel, which may serve for a contemplation, and yield a foretaste of our inheritance. He writes, "Here is as much said as can be, but words are too weak to utter it. For quality there is in heaven joy and pleasures; for quantity, a fulness, a torrent whereat they drink without let or loathing; for constancy, it is at God's right hand, Who is stronger than all, neither can any take us out of His hand; it is a constant happiness without intermission: and for perpetuity it is for evermore. Heaven's joys are without measure, mixture, or end."

Here are some other OT uses of rejoice. Notice who is rejoicing and what they are rejoicing over.

(Save me) That I may tell of all Thy praises, That in the gates of the daughter of Zion I may rejoice in Thy salvation. (Psalm 9:14) (Spurgeon's note)

But I have trusted in Thy lovingkindness; My heart shall rejoice in Thy salvation. (Psalm 13:5) (Spurgeon's note)

There is joy and feasting within doors, for a glorious guest has come, and the fatted calf is killed. Sweet is the music which sounds from the strings of the heart. But this is not all; the voice joins itself in the blessed work, and the tongue keeps tune with the soul, while the writer declares,

I will sing unto the Lord.

"I will praise thee every day, Now thine anger's past away;
Comfortable thoughts arise From the bleeding sacrifice."

Be glad in the LORD and rejoice, you righteous ones, And shout for joy, all you who are upright in heart. (Psalm 32:11) (Spurgeon's note)

Be glad. Happiness (joy) is not only our privilege, but our duty. Truly we serve a generous God, since He makes it a part of our obedience to be joyful. How sinful are our rebellious murmurings! How natural does it seem that a man blest with forgiveness should be glad! We read of one who died at the foot of the scaffold of overjoy at the receipt of his monarch's pardon; and shall we receive the free pardon of the King of kings, and yet pine in inexcusable sorrow?

In the Lord. Here is the directory by which gladness is preserved from levity. We are not to be glad in sin, or to find comfort in corn, and wine, and oil, but in our God is to be the garden of our soul's delight. That there is a God and such a God, and that He is ours, ours for ever, our Father and our reconciled Lord, is matter enough for a never ending psalm of rapturous joy.

And rejoice, ye righteous, redouble your rejoicing, peal upon peal. Since God has clothed His choristers in the white garments of holiness, let them not restrain their joyful voices, but sing aloud and shout as those who find great spoil.

And shout for joy, all ye that are upright in heart. Our happiness should be demonstrative; chill (cold) penury (extreme paucity) of love often represses the noble flame of joy, and men whisper their praises decorously where a hearty outburst of song would be far more natural. It is to be feared that the church of the present day, through a craving for excessive propriety, is growing too artificial; so that enquirers' cries and believers' shouts would be silenced if they were heard in our assemblies. This may be better than boisterous fanaticism, but there is as much danger in the one direction as the other. (Ed note: Amen!) For our part, we are touched to the heart by a little sacred excess, and when godly men in their joy over leap the narrow bounds of decorum, we do not, like Michal, Saul's daughter, eye them with a sneering heart. Note how the pardoned are represented as upright, righteous, and without guile; a man may have many faults and yet be saved, but a false heart is everywhere the damning mark. A man of twisting, shifty ways, of a crooked, crafty nature, is not saved, and in all probability never will be; for the ground which brings forth a harvest when grace is sown in it, may be weedy and waste, but our Lord tells us it is honest and good ground. Our observation has been that men of double tongues and tricky ways are the least likely of all men to be saved: certainly where grace comes it restores man's mind to its perpendicular, and delivers him from being doubled up with vice, twisted with craft, or bent with dishonesty. Reader, what a delightful Psalm! Have you, in perusing it, been able to claim a lot in the goodly land? If so, publish to others the way of salvation.

Here Paul gives a command (imperative mood) for the Philippians to continually (present tense) rejoice. (see present imperative)

Wuest says they are to "go on constantly rejoicing in the Lord".

Paul writes that joy is one component of the fruit of the Spirit...

But the fruit of the Spirit is love, joy, peace, patience, kindness, goodness, faithfulness (See notes on Joy in Galatians 5:22)

The Greek dramatist Aeschylus (525-456 BC) concluded,

Joy [is] a beauteous spark divine.

To ancient Greeks it was a greeting, a wish for the happiness of one's friend. It was also the object of fellowship, as seen in the festal joy of religion. Greeks spoke, as we do, of "tears of joy."

Homer saw joy as being rooted in human passions, as we may "feel" joyful. On the other hand, the Greek Stoics (who are mentioned in Acts 17:18) had no room for joy, which they regarded as a false judgment of reality. If you felt joyful, you must be ignorant of the facts! Most of us know people like that.

The famous Austrian composer Franz Joseph Haydn (1732-1809) declared:

When I think of God, my heart is so full of joy that the notes leap and dance as they leave my pen; and since God has given me a cheerful heart, I serve Him with a cheerful spirit.

Oswald Chambers the famous devotional writer concluded that

The joy that Jesus gives is the result of our disposition being at one with His own disposition.

C. S. Lewis wrote that...

Joy is the serious business of heaven.

Bernard Ramm, a theologian, wrote that

Jesus Christ can put joy into the joyless work of the 20th century.

Keith Miller wrote that

Joy seems to be distilled from a strange mixture of challenge, risk, and hope.

Samuel Shoemaker said that

The surest mark of a Christian is not faith, or even love', but joy.

A noted preacher in England H. W. Webb-Peploe once said that...

Joy is not gush; joy is not jolliness. Joy is perfect acquiescence in God's will because the soul delights itself in God Himself.

Since joy is a fruit of the Spirit it follows that those who can most readily obey Paul's command to rejoice are those who are continually being filled with (controlled by - see note Ephesians 5:18) the Holy Spirit.  The key to the Christian's joy is not found in circumstances or people but in the Person of Christ as indicated by the association with the phrase in the Lord . This phrase is found 9 times in this short (joyful, joy full, joy filled) letter...

Philippians 1:14 (note) and that most of the brethren, trusting in the Lord because of my imprisonment, have far more courage to speak the word of God without fear.

Philippians 2:19 (note) But I hope in the Lord Jesus to send Timothy to you shortly, so that I also may be encouraged when I learn of your condition.

Philippians 2:24 (note) and I trust in the Lord that I myself also shall be coming shortly.

Philippians 2:29 (note) Therefore receive him in the Lord with all joy, and hold men like him in high regard;

Philippians 3:1 (note) Finally, my brethren, rejoice in the Lord. To write the same things again is no trouble to me, and it is a safeguard for you.

Philippians 4:1 (note) Therefore, my beloved brethren whom I long to see, my joy and crown, so stand firm in the Lord, my beloved.

Philippians 4:2 (note) I urge Euodia and I urge Syntyche to live in harmony in the Lord.

Philippians 4:4 (note) Rejoice in the Lord always; again I will say, rejoice!

Philippians 4:10 (note) But I rejoiced in the Lord greatly, that now at last you have revived your concern for me; indeed, you were concerned before, but you lacked opportunity.

Paul speaks of joy before warning his readers of some of the top joy stealers, especially the false teachers who have crept in among us and claim to be members of the body of Christ ("dogs...evil workers...false circumcision"). Watch out for these individuals because they love to steal your joy with their clever lies and devious deceptions.

TO WRITE THE SAME THINGS IS NO TROUBLE TO ME: ta auta graphein (PAN) humin emoi men ouk okneron:

Same things -- a good teacher emphasizes repetition. The probability is that he is going to take up again several details he had already mentioned, such as, those who were really spiritual antagonists (see notes Philippians 1:15; cp 3:2, 3:18); the need of standing fast (see notes Philippians 1:27; cp 4:1); dissensions and the need of unity (see notes Philippians 1:17; Philippians 2:2; 2:3; 2:4; cp 4:2); the antidote, a glorying in Christ and allusions to His union with His people (Philippians 1:20; 21; 22; 23; ; 2:5ff; cp Philippians 3:3, 3:15; 4:7).

Spurgeon comments...

To go over the same old truths again and again, to proclaim the same precepts, and teach the same doctrines, is not grievous to us, and it is safe for you to hear these things again and again. If they have not made their due impression upon you already, perhaps they will do so when they are repeated in your hearing. At any rate it is safe for you to hear or read over and over again the old, old story with which you are already familiar.

Some hearers are like the Athenian academicians; they want continually to hear something new. The apostle says, “To have the same things written to you, is safe.” So is it for you, dear friends; to have the same gospel, the same Jesus, the same Holy Spirit, made known to you, is safe. New doctrine is dangerous doctrine.

Saying the same thing over and over again is Safe, for your minds do not catch the truth at the first hearing, and your memories are slippery.

Trouble (3636) (okneros is from okneo = to shrink, to hesitate, to delay) means that which causes reluctance or is tedious or bothersome (upsets a person's composure or which annoys and suggests interference with one's comfort or peace of mind). It describes being afraid to act, hesitating, shrinking or lazy.

Paul is saying it is not bothersome for him to repeat truth so that they might be kept from being tripped up by false teaching. As Eadie phrases it "To repeat the same truth is to me no task of irksome monotony." Biblical truth is always the best safeguard from error!

Okneros is found 3 times in the NAS (Matthew; Romans; Philippians) and is translated .lagging behind, 1; lazy, 1; trouble, 1. The KJV renders it grievous, 1; slothful, 2.

TDNT writes that...

Like oknos, which means “hesitation” through weariness, sloth, fear, bashfulness, or reserve, okneros is used a. of persons in the sense of “showing oknos,” “hesitating,” “anxious,” “negligent,” “slothful.” It thus denotes one who for various reasons or difficulties does not have the resolution to act... In the OT (Septuagint or LXX) okneros is often used in connection with rules of practical wisdom. Industry and work are here part of pious but prudent conduct. Thus okneros... depicts the slothful man who lacks the resolve to get to work (Pr 6:6, 9), who lets inconveniences stop him (Pr 20:4), or who, having no resolution, never moves on from the will to the deed (Pr 21:25). In contrast the continually active wife, who takes pleasure in work, is extolled (Pr 31:27).

Impelled by the Spirit to equip Christians adequately for salvation, Paul (here in Phil 3:1) overcomes the dislike or distaste which might arise through repetition of his admonition. (Kittel, G., Friedrich, G., & Bromiley, G. W. Theological Dictionary of the New Testament.  Eerdmans)

Vincent writes that okneros is found here and in...

Matt. 25:26; Ro 12:11, in both (these latter) instances rendered slothful. (Ed note: thus conveying more the idea of lazy, idle, not active) From okneo to delay. Hence, in classical Greek, shrinking, backward, unready. The idea of delay underlies the secondary sense, burdensome, troublesome. It is the vexation arising from weary waiting, and which appears in the middle English irken to tire or to become tired, cognate with the Latin urgere to press, and English irk, irksome, work.

AND IT IS A SAFEGUARD FOR YOU: humin de asphales: (Phil 2:17,18; 2 Pe1:12-15; 3:1) 

"Spiritual joy is the best safety against error" (Jamieson, Fausset, and Brown)

Safeguard (804) (asphales from a = w/o + sphallo = throw down, trip up, totter, bring to the ground, make someone fall) literally means that which cannot be thrown down, tripped up, tottered or overthrown. It describes that which is secure and safe from stumbling or falling.

Asphales thus means firm, sure, secure, safety, unshakeable, certain, steady, immovable (as of the anchor in Hebrews 6:19 - see below - or in Septuagint referring to the sky above in Pr 8:28) and then figuratively referring to a state of safety, stability and security which can be relied on and hence free from danger and secure from peril. Asphales describes something that cannot be made to totter when put to the test. In Acts 2:36 the related adverb asphalos means certainly, surely, speaking of that which is known beyond a doubt.

NIDNTT has the following note on the uses of this word group in classic literature...

Asphaleia occurs in classic Greek. with the following meanings: security against stumbling (Thuc., History, 3, 22), assurance from danger (Aeschylus onwards), caution (in post-Christian writings), assurance, certainty (Thuc. History, 2, 11), the certainty or convincing nature of an argument (Xenophon, Memorabilia, 4, 6, 15), and as a security, bond or pledge as a technical law term (Arrianus, Epicteti Dissertationes, 2, 13, 7; BGU 1149, 24; P. Teb. 293, 19; The Amherst Papyri, 78:16). The adjective asphales occurs from Homer onwards in the sense of immovable, steadfast, unshaken, unfailing both literally and in the case of friends etc., and safe both literally and figuratively. The verb. asphalizo is used in the sense of secure, safeguard and, in 1st cent. B.C. literature, arrest. (Brown, Colin, Editor. New International Dictionary of NT Theology. 1986. Zondervan)

Compare Luke's use of the noun form asphaleia in his introductory comments writing... "so that you might know the exact (asphaleia) truth (logos - word) about the things you have been taught" (Luke 1:4) thus speaking of teaching or instruction which affords certainty and reliability.

The related noun asphaleia is found in the Septuagint or LXX of Deut 12:10 where Moses records that...

"When you cross the Jordan and live in the land which the LORD your God is giving you to inherit, and He gives you rest from all your enemies around you so that you live in security (asphaleia)" (Dt 12:10)

This word group was also used as a technical legal term for keeping a prisoner securely guarded security (see Acts 5:23).

The noun form asphaleia (803) is used by Paul in the phrase "Peace and safety (asphaleia)" in 1Thes 5:3, where the "safety" or security from peril is false and deceptive for it is focused on this world which is passing away instead of looking for the blessed hope and appearing of the glory of our great God and Savior, Christ Jesus (see note Titus 2:11).

The verb form asphalizo (805) is used by Matthew referring to Jesus' burial site where it was said "give orders for the grave to be made secure (asphalizo)" (Mt 27:64) and Pilate's orders "make it secure (asphalizo) as you know how (referring to Jesus' grave). And they went and made the grave secure (asphalizo), and along with the guard they set a seal on the stone." (Mt 27:65-66). Luke uses the verb form to describe the incarceration of Paul and Silas writing that the jailer "threw them into the inner prison, and fastened (asphalizo) their feet in the stocks." (Acts 16:23).

Aphales is used in Hebrews presenting every believer with a powerful word picture of our unshakeable position safe in Christ...

(In the storms and trials of life) This hope (embodied in Christ Himself and since we are "in Christ" this reflects the truth that our glorification is as certain as if it had already happened which is truth that should keep us from drifting on the wild waves of doubt and despair) we have as an anchor (note that the anchor is not cast onto the shifting sands of this world but actually into the sanctuary in heaven = safe and secure!) of the soul, a hope both sure (aphales) and steadfast and one which enters within the veil (see note Hebrews 6:19)

Aphales is used 5 times in the NAS (Acts 3x; Philippians; Hebrews) translated certain, 1; definite, 1; facts, 1; safeguard, 1; sure, 1.

Acts 21:34 But among the crowd some were shouting one thing and some another, and when he could not find out the facts (literally = not being able to know the certainty) on account of the uproar, he ordered him to be brought into the barracks.

Acts 22:30 But on the next day, wishing to know for certain why he had been accused by the Jews, he released him and ordered the chief priests and all the Council to assemble, and brought Paul down and set him before them.

Acts 25:26 "Yet I have nothing definite (no certain thing) about him to write to my lord. Therefore I have brought him before you all and especially before you, King Agrippa, so that after the investigation has taken place, I may have something to write.

Philippians 3:1 (note) Finally, my brethren, rejoice in the Lord. To write the same things again is no trouble to me, and it is a safeguard for you.

Hebrews 6:19 This hope we have as an anchor of the soul, a hope both sure and steadfast and one which enters within the veil,