As William Kelly observes...

The Epistle then turns from our holy trials to our unholy ones, and shows their source to be, not in God, but in sinful man. (Comment: The former must be endured, the latter resisted.)

Wuest has an interesting paraphrase adding the word "sin" (not in the Greek) to emphasize that the test is not for good but for evil. God does test men, but He does not tempt men to do evil. There is a substantial difference and that is what Wuest's paraphrase accentuates...

Let no man be saying when he is being solicited to sin, "By God I am being solicited to sin", for God is incapable of being solicited to sin, the source of the solicitations being evils, and He himself solicits no one to sin

Let...say (3004) means to speak or talk, with an apparent focus upon content of what is said. Note that this is not a suggestion but a command in the present imperative with a negative, which means in essence "Stop accusing God!". "Cease saying when you are being tempted that it's God's fault!"

When he is tempted - Notice he does not say "if" but "when". Temptation is a sure thing! If you feel you are not being tempted then chances are you are already deceived by the temptation and you don't even realize your dire state!

As J C Ryle writes...

Let us beware of making light of temptation because they seem little and insignificant. There is nothing little that concerns our souls.

F P Wood rightly says instructs us regarding the "value" of temptations when he says...

Temptation is not sin; it is the call to battle.

The point is that you are in a war, a continual war against your soul, not simply a momentary skirmish. Your flesh, the evil world system and the evil one are resolutely determined to take you down! Stop being deceived regarding this strategic truth, lest you be swept downstream by the strong pull of the temptation that comes from within.

W H Griffith said that...

Satan tempts to bring out the bad; God tests to bring out the good. (Or as someone else has said "Satan tempts us to bring out the worst in us but God tests us to bring out the best.")

Peter warned his readers (who were being tested/tempted - see notes 1 Peter 1:6; 1:7)...

Beloved (note his affectionate address [similar to James] before he explains a serious, hard truth), I urge (present tense = continually. Parakaleo - I come alongside you. I know the power and pull of temptation first hand. I fell. But God gave me grace to repent and return that I might now strengthen you with this warning. See Luke 22:32-34, Mt 26:74, 75, Acts 2:14ff, cp Acts 3:19) you as aliens and strangers to abstain from fleshly lusts, which wage war (continually = present tense) against the soul. (see note 1 Peter 2:11)

John Quincy Adams wrote that...

Every temptation is an opportunity of our getting nearer to God.

Martin Luther spoke of what the flesh means for evil God can use for good writing that...

My temptations have been my masters in divinity....Temptation and adversity are the two best books in my library.

Tempt (3985)(peirazo from the noun peira = test from peíro = perforate, pierce through to test durability of things) is a morally neutral word simply meaning “to test”. Whether the test is for a good (as it proved to be in Heb 11:17) or evil (Mt 4:1 "Then Jesus was led up by the Spirit into the wilderness to be tempted by the devil") depends on the intent of the one giving the test and also on the response of the one tested. (See study of similar word dokimazo)

Wiersbe writes that...

A temptation is an opportunity to accomplish a good thing in a bad way, out of the will of God. We think of sin as a single act, but God sees it as a process. Adam committed one act of sin, and yet that one act brought sin, death, and judgment on the whole human race. James described this process of sin in four stages. (Desire, Deception, Disobedience, Death)  (Wiersbe, W: Bible Exposition Commentary. 1989. Victor or Logos)

Note that the verb peirazo here translated as tempted is in the same word group as the noun peirasmos which is translated trial (James 1:2; James 1:12). Peirazo/peirasmos when used of God reflects His testing or trying a believer's faith, but never in the sense of tempting the believer to sin. In Peter's first epistle it is clear that God's purpose is not to cause to sin and not to destroy but to refine.

In this you greatly rejoice, even though now for a little while, if necessary (his implication is trials are necessary), you have been distressed by various trials (peirasmos), that the proof of your faith, being more precious than gold which is perishable, even though tested by fire, may be found to result in praise and glory and honor at the revelation of Jesus Christ (see notes 1 Peter 1:6; 1:7)

Beloved (he is addressing believers), do not be surprised (present imperative + a negative = "Stop being surprised") at the fiery ordeal among you, which comes upon you for your testing (peirasmos), as though some strange thing were happening to you; but to the degree that you share the sufferings of Christ, keep on rejoicing (present imperative  = command to make rejoicing your "lifestyle" even in trials - only possible by the manifold grace of God and the inner strengthening by the indwelling Holy Spirit); so that (introduces the purpose of the testing) also at the revelation of His glory, you may rejoice with exultation. If you are reviled for the name of Christ, you are blessed, because the Spirit of glory and of God rests upon you. (see notes 1 Peter 4:12; 13; 14)

Comment: God has never promised that we would miss the storm, but He has promised that we would make the harbor. When God puts His own people into the furnace, He keeps His eye on the clock and His hand on the thermostat. He knows how long and how much. (Wiersbe)

Peirazo is used 3 times in this passage each in the present tense ("continually tested"). In the first use, it is clear that this tense indicates that the test is never-ending in this life but it will end in the life to come when we are delivered not only from the presence of sin but the pleasure of sin.

The gods of heathen imagination are always conceived both as liable to temptation to moral evil, and as themselves tempters. The conception of their character comes from man's wicked heart, and the stream cannot rise higher than its source. (Commentary on James)

Tempted (551) (apeirastos from a = negative + peirazo = to test) is an adjective which means literally untempted or untried. It speaks of not being able to be tempted.

Himself (autos) emphasizes God and the fact that He never solicits to sin. As stated elsewhere, God does allow "tests" in our life, but His purpose is never to cause us to stumble, but to humble us and refine us and make us more like His Son. We are the problem when the tests come, not God! Every test is an opportunity to grow in grace or stumble into sin. In the present context however James has shifted from actual tests to true temptations to do evil.

Cannot be tempted - Combines the adjective apeirastos with eimi (to be) in the present tense (estin). God's is continually untempted by evil. Wuest says "God is incapable of being solicited to sin".

God is Light, and in Him is no darkness at all” (1 John 1:5)

Your eyes are too pure to approve evil, and You can not look on wickedness with favor (Hab 1:13)

Evil (2556) (kakos) basically denotes a lack of something and so it means bad or not as it ought to be. Kakos is a neuter plural adjective without an article which denotes those things that have the moral quality of being base, bad, degrading, and clearly the very opposite of those things that are ethically and morally good, wholesome and beneficial.

In the "Lord's Prayer" we pray “And lead us not into temptation” but this is not implying that God tempts us to do evil. What it means is something like “don’t allow us to come under the sway of temptation that will over power us and cause us to sin.” (see note Matthew 6:13)

MacDonald comments that...

Man is always ready to shift responsibility for his sins. If he cannot blame God, he will adopt an approach of modern psychology by saying that sin is a sickness. In this way he hopes to escape judgment. But sin is not a sickness; it is a moral failure for which man must give account. Some even try to blame inanimate things for sin. But material “things” are not sinful in themselves. Sin does not originate there. James tracks the lion to its den when he says: “Each one is tempted when he is drawn away by his own desires and enticed.” Sin comes from within us, from our old, evil, fallen, unregenerate nature. Jesus said, “Out of the heart proceed evil thoughts, murders, adulteries, fornications, thefts, false witness, blasphemies” (Matt. 15:19).

Matthew Poole explains some objections that might be raised...

“Objection.” God is said to be tempted, Ex 17:2, 7 Deut 6:16 Ps 78:41; and to tempt, Ge 22:1, (KJV "tempt", NAS - "test") Deut 8:2 13:3.

“Answer.” Both are to be understood of temptations of exploration, or for the discovery of something that was before hidden. Men tempt God, that they may know what he will do; God tempts men, that they (not he, for he knows it already) may know what themselves will do, which then appears, when the temptation draws it out; but neither is to be understood of the temptation here spoken of, viz. of seduction, or drawing into sin. God tempts by giving hard commands, Ge 22:1; by afflicting, as in Job’s case; by letting loose Satan or other wicked instruments to tempt, 1 Ki 22:22; by withholding his grace and deserting men, 1 Sam 28:15; by presenting occasions which corruption within improves unto sin, and by ordering and governing the evil wills of men, as that a thief should steal out of this flock rather than that, that Nebuchadnezzar should come against Jerusalem rather than Rabbah, Eze 21:21, 22. But God doth not tempt by commanding, suggesting, soliciting, or persuading to sin. (Matthew Poole's Commentary on the New Testament)

F B Hole writes...

God Himself is above all evil. It is absolutely foreign to His nature. It is as impossible for Him to be tempted with evil as it is impossible for Him to lie. Equally so it is impossible for Him to tempt anyone with evil though He may permit His people to be tempted with evil, knowing well how to overrule even that for their ultimate good. The real root of all temptation lies within ourselves, in our own lusts. We may blame the enticing thing which from without was presented to us, but the trouble really lies in the desires of the flesh within.

Let us lay hold of this fact and honestly face it. When we sin the tendency is for us to lay a great deal of the blame on our circumstances, or at all events on things without, when if only we are honest before God we have no one and nothing to blame but ourselves. How important it is that we should thus be honest before God and judge ourselves rightly in His presence, for that is the high road to recovery of soul. Moreover it will help us to judge and refuse the lusts of our hearts, and thus sin will be nipped in the bud. Lust is the mother of sin. If it works it brings forth sin, and sin carried to completion brings forth death. (James Commentary -Plymouth Brethren)

A B Simpson writes that...

While temptation is not directly from God, yet it is overruled by God, and made one of His instrumentalities of blessing to us. God does not "tempt any man, neither is tempted with evil," yet God permits us to be tempted. God put our first parents into temptation and He made it possible for them either to choose or refuse; gave them a nature subject to temptation, and while it might overcome them, it might also be overcome. God does not tempt any man, yet He does allow this to be one of the classes in the school of faith and holiness. He even led Jesus Christ, His own Son, into the wilderness by the Spirit to be tempted of the devil. Think it not a strange thing then, dear friends, if your life is called to pass through the ordeal of the conflict, evil from within and from without, not merely things that grieve, afflict and distress you, but things that tend to make you do wrong and draw you from the path of righteousness, truth and godliness. They will come. God wants you to be forewarned and forearmed, and to know it is better that they should come to you, if you but take the panoply of God and come through in victory. (A. B. Simpson. Christ in the Bible - James)

But (de) introduces the contrast with the thought that God could tempt us to sin. James says to the contrary that is not so and explains what is so. God is not the culprit. Lust that dwells within us is the agent of deceit.

Each one (1538) (hekastos) means each one of an aggregate. Hekastos stresses the universal experience of temptation individually. The idea is every single person! In short, there is not man or woman so "holy" or "pious" that they are beyond temptation. Neither is there anything anyone can do to completely escape this temptation. Even age does not remove the temptation. Like the 78 year old saint who responded to the pastor at his surprise that this elderly saint was still vulnerable to sexual temptation at his age...

Son, just because I’m old doesn’t mean the blood doesn’t flow through my veins. The difference between we old men and you young men is this: we know we’re sinners. We’ve had plenty of experience. You kids haven’t figured that out yet. (in Leadership [Fall, 1992], pp. 74-75).

The saintly pastor Charles Simeon referred to the source of temptation in each one using the metaphor that we are all carrying around highly flammable material within our bodies! His point of course was that we need to be very careful not to light the fuse, lest the powder flare up and explode!

Calvin wrote that James’ object in this section is

to teach us that there is in us the root of our own destruction.

Don't let anyone deceive you into thinking our old Sin nature or the wicked flesh has been eradicated in the believer, for Scripture does not teach this aberration, at least not until we attain glory!

The point is that since temptation never comes from God, we can (should) never blame Him when we are tempted. When God asked Adam if he had eaten from the tree he was commanded not to eat from, he actually did not answer directly instead indirectly blaming God for his predicament...

And the man said, "The woman whom Thou gavest to be with me, she gave me from the tree, and I ate." (Genesis 3:13)

So don't try to shift the blame onto God when you are tempted and sin! Don't use the lame logic that since God is sovereign over all, He is also sovereign over my sin. So it's not my fault. He could have stopped me! Don't say things like - "God, you expect too much from me", "God, you have made things too difficult for me", "God, you have not given me the same grace and power to resist temptation that you have given others; this is just my temperament; I can't help myself", "God, you created me this way". Don't blame God for your temptation to sin!

So as you learn to deal correctly with temptation first recognize that you cannot blame anyone else but yourself. You need to take personal responsibility. There is a tendency in us to find excuses for our sin. There is no place for “The Devil made me do it” attitude. And don't blame bad circumstances, "bad" genes or the bad culture.

Ropes writes that ...

Paul in 1 Cor. 10:13 makes a similar exhortation in curiously different form: “Do not excuse yourselves by thinking that your temptation is greater than man can bear.” (Ropes, J. H. A Critical and Exegetical Commentary on the Epistle of St. James)

Notice that James does not blame your parents, your spouse, your job, your kids, etc. He doesn't label it as a disease or a dysfunction. He doesn't even blame the devil in this section because he wants to be sure we first acknowledge that we are the primary source for temptation. When you get up tomorrow morning and look at your face in the mirror, you are seeing your greatest problem! D L Moody recognized this basic principle quipping that...

I have more trouble with D. L. Moody than with any man I know.

Thomas a Kempis put it this way...

There is no order so holy, no place so secret, where there will be no temptation.

Those who think there are capable of attaining to sinlessness in this life are deceived and are in a precarious state for Paul writes...

let him who thinks he stands take heed (present imperative) lest he fall. (1Cor 10:14) (for as Matthew Henry rightly warned "The best of saints may be tempted to the worst of sins.")

Steven Cole has the following illustration...

A man was on a diet and struggling. He had to go downtown and as he started out, he remembered that his route would take him by the doughnut shop. As he got closer, he thought that a cup of coffee would hit the spot. Then he remembered his diet. That’s when he prayed, “Lord, if You want me to stop for a doughnut and coffee, let there be a parking place in front of the shop.” He said, “Sure enough, I found a parking place right in front—on my seventh time around the block!” As Robert Orben said, “Most people want to be delivered from temptation but would like it to keep in touch” (Reader's Digest [8/86], p. 35).

Allow me to state the obvious: You will not make it as a Christian if you do not learn to overcome temptation. In the parable of the sower, Jesus taught that some make a profession of faith and begin to show signs of growth, but the heat of trials or the more subtle thorns of worldly desires cause the plant to die (see Luke 8:11-15). As I understand that parable, it is only those plants that endure and produce fruit that represent true believers. Because the enemy is strong and the lusts of the flesh are so powerful, you must learn to recognize and overcome temptation. If you do not, James says, you are on the path that leads to death.

I think that as he wrote this, James probably had in mind the graphic story in Proverbs 7 of the young man lacking sense, who succumbs to the loose woman’s enticement. His first mistake was that he passed near the corner where she lived (Prov. 7:8). As “luck” would have it, at that very moment, she happens to come out of her door. As further “luck” would have it, her husband has gone on a long trip. “With her many persuasions she entices him; with her flattering lips she seduces him. Suddenly he follows her as an ox goes to the slaughter, or as one in fetters to the discipline of a fool, until an arrow pierces through his liver; as a bird hastens to the snare, so he does not know that it will cost him his life” (Pr 7:21-23). Proverbs 7:26-27 concludes, “For many are the victims she has cast down, and numerous are all her slain. Her house is the way to Sheol, descending to the chambers of death.”

James gives us a strategy for overcoming the deadly lure of temptation: To overcome temptation, recognize its source, its force, and its course. (James 1:13-15 The Source, Force, and Course of Temptation)

The flesh is evil and still lives in believers and will do so until we go to be with Jesus. Don't try to get rid of it like some tribes of primitive Indians did! In Chicago's Field Museum are skulls from ancient Indians and some are called trepanned skulls because they have holes bored in them. The primitive people used would bore holes in the skulls of living people in a vain attempt to let the demons out.

Tempted (3985)(peirazo - click discussion of this verb in verse 13) is in the which once again emphasizes that temptation is a lifelong issue. The Bible does not teach a temptation free nor a sinless state in this life but only in the one to come. Notice the verb is in the present tense indicating that we are continually being (passive voice = another source, in this context the old flesh) tempted.

All temptation tests your faith...
All testing of your faith is a temptation
to forsake the faith
- John Piper

John Piper although discussing Satan and not our fallen flesh as the source of temptation (in this specific sermon) has a useful analysis of the relationship of testing (James discusses this in James 1:2ff - see notes) and temptation (James 1:13; 14