From whence come wars and fightings among you? come they not hence, even of your lusts that war in your members?
From whence come wars and fightings — Quarrels and wars among you, quite opposite to this peace? Is it not from your pleasures - Your desires of earthly pleasures.
Which war — Against your souls.
In your members — Here is the first seat of the war. Hence proceeds the war of man with man, king with king, nation with nation.
 Ye lust, and have not: ye kill, and desire to have, and cannot obtain: ye fight and war, yet ye have not, because ye ask not.
Ye kill — In your heart, for "he that hateth his brother is a murderer." Ye fight and war - That is, furiously strive and contend.
Ye ask not — And no marvel; for a man full of evil desire, of envy or hatred, cannot pray.
 Ye ask, and receive not, because ye ask amiss, that ye may consume it upon your lusts.
But if ye do ask, ye receive not, because ye ask amiss - That is, from a wrong motive.
 Ye adulterers and adulteresses, know ye not that the friendship of the world is enmity with God? whosoever therefore will be a friend of the world is the enemy of God.
Ye adulterers and adulteresses — Who have broken your faith with God, your rightful spouse. Know ye not that the friendship or love of the world - The desire of the flesh, the desire of the eye, and the pride of life, or courting the favour of worldly men, is enmity against God? Whosoever desireth to be a friend of the world - Whosoever seeks either the happiness or favour of it, does thereby constitute himself an enemy of God; and can he expect to obtain anything of him?
 Do ye think that the scripture saith in vain, The spirit that dwelleth in us lusteth to envy
Do you think that the scripture saith in vain — Without good ground. St. James seems to refer to many, not any one particular scripture. The spirit of love that dwelleth in all believers lusteth against envy - Galatians 5:17; is directly opposite to all those unloving tempers which necessarily flow from the friendship of the world.
 But he giveth more grace. Wherefore he saith, God resisteth the proud, but giveth grace unto the humble.
But he giveth greater grace — To all who shun those tempers.
Therefore it — The scripture.
Saith, God resisteth the proud — And pride is the great root of all unkind affections. Proverbs 3:34
 Submit yourselves therefore to God. Resist the devil, and he will flee from you.
Therefore by humbly submitting yourselves to God, resist the devil - The father of pride and envy.
 Draw nigh to God, and he will draw nigh to you. Cleanse your hands, ye sinners; and purify your hearts, ye double minded.
Then draw nigh to God in prayer, and he will draw nigh unto you, will hear you; which that nothing may hinder, cleanse your hands - Cease from doing evil.
And purify your hearts — From all spiritual adultery. Be no more double minded, vainly endeavouring to serve both God and mammon.
 Be afflicted, and mourn, and weep: let your laughter be turned to mourning, and your joy to heaviness.
Be afflicted — For your past unfaithfulness to God.
 Speak not evil one of another, brethren. He that speaketh evil of his brother, and judgeth his brother, speaketh evil of the law, and judgeth the law: but if thou judge the law, thou art not a doer of the law, but a judge.
Speak not evil one of another — This is a grand hinderance of peace. O who is sufficiently aware of it! He that speaketh evil of another does in effect speak evil of the law, which so strongly prohibits it.
Thou art not a doer of the law, but a judge — Of it; thou settest thyself above, and as it were condemnest, it.
 There is one lawgiver, who is able to save and to destroy: who art thou that judgest another?
There is one lawgiver that is able — To execute the sentence he denounces.
But who art thou — A poor, weak, dying worm.
 Go to now, ye that say, To day or to morrow we will go into such a city, and continue there a year, and buy and sell, and get gain:
Come now, ye that say — As peremptorily as if your life were in your own hands.
 For that ye ought to say, If the Lord will, we shall live, and do this, or that.
Instead of your saying — That is, whereas ye ought to say.
 Therefore to him that knoweth to do good, and doeth it not, to him it is sin.
Therefore to him that knoweth to do good and doeth it not — That knows what is right, and does not practise it.
To him it is sin — This knowledge does not prevent, but increase, his condemnation.