James 1:5

If any of you lack wisdom
This shows that the perfection before spoken of is not to be understood as in this life, since the apostle immediately supposes lack of wisdom in them; for this is not said in a form of doubting, whether they wanted it or not, but rather as supposing, and taking it for granted that they did; and in the first, and primary sense of the words, it intends wisdom to behave aright under temptations or afflictions. Saints often want wisdom to consider God as the author of them, and not look upon them as matters of chance, or impute them merely to second causes; but to regard them as coming from the hand of God, and as his hand upon them, as Job did; who does not ascribe his calamities to the thieving Chaldeans and Sabeans, to the boisterous wind, and to the malice of Satan, but to God: they want wisdom to observe the sovereignty of God in them, and bow unto it, and be still, and know that he is God, who does all things well and wisely; and likewise to see and know that all are in love, and in very faithfulness, and for good; as well as to see his name, to hear his rod, and him that has appointed it, his voice in it, his mind and meaning, and what he designs by it; as likewise to learn the useful lessons under it, and particularly to take the cross well, to bear it patiently, and even to count it all joy, and reckon it to be right, necessary, and useful: it requires much wisdom to learn all this, and act up to it. Moreover, this may be applied to all other cases, in which wisdom is wanted; men want wisdom to conduct them in the common affairs of life, and especially the people of God; for the children of the world are wiser in their generation, for themselves and posterity, and in the management of worldly affairs, than the children of light; and also to observe the providences of God, and the footsteps of Providence, and to follow them; and likewise to make a right use of providences, and behave suitably under them, and not be lifted up too much in prosperity, nor be cast down, and too much distressed in adversity; but to consider, that the one is set against the other, and both work together for good. Saints have need of wisdom in things spiritual; they want more grace, which is the truest wisdom, and a larger knowledge of the Gospel, which is the wisdom of God, the hidden wisdom of God; and they lack wisdom to know how to walk towards them that are without, and towards them that are within, so as becomes the Gospel of Christ: and as this is more or less the case of everyone

let him ask of God
wisdom; of God the Father, who is the only wise God, who has abounded in creation, in providence, and, above all, in redemption and grace, in all wisdom and prudence; and of his Son Jesus Christ, who is the wisdom of God, and has all the treasures of wisdom and knowledge in him; and of the Spirit of God, who is a Spirit of wisdom and revelation in the knowledge of Christ, and all divine things:

that giveth to all men liberally;
God is the giver of all good things, in nature, providence, and grace; every good and perfect gift comes from him, and therefore he, and he only, should be applied unto: and he gives to "all men" the bounties of his providence; and to all that ask, and call upon him in sincerity, the riches of his grace; even to Jews and Gentiles, high and low, rich and poor, greater or lesser sinners; all which he gives "liberally", readily, and at once, freely and cheerfully, and largely and abundantly; not grudgingly, sparingly, and with a strait hand, but with an open one, and in a very extensive manner.

And upbraideth not;
with former sins and transgressions, with former miscarriages and misconduct; or with former kindnesses, suggesting that he had given largely already, and his favours had been despised or abused; or he had been treated with ingratitude and neglect; in which manner sometimes men put off those that apply unto them, but so does not God; wherefore every word here used is encouraging to go to God for wisdom: yea, it follows,

and it shall be given him;
God has said it, Christ has promised it, and the apostle might, with certainty, say it after them, and all experience confirms the truths of it; See ( Matthew 7:7 Matthew 7:8 ) ( John 14:13 John 14:14 John 14:16 John 14:23 ) .