John Calvin on James 1:4

4 But let patience have her perfect work. As boldness and courage often appear in us and soon fail, he therefore requires perseverance. “Real patience,” he says, “is that which endures to the end.” For work here means the effort not only to overcome in one contest, but to persevere through life. His perfection may also he referred to the sincerity of the soul, that men ought willingly and not feignedly to submit to God; but as the word work is added, I prefer to explain it of constancy. For there are many, as we have said, who shew at first an heroic greatness, and shortly after grow weary and faint. He therefore bids those who would be perfect and entire, “Perfect, τέλειοι,” fully grown, mature; “entire, ὁλόχληζοι,” complete, no part wanting. The first refers to the maturity of grace; and the second to its completeness, no grace being wanting. They were to be like men full grown, and not maimed or mutilated, but having all their members complete. to persevere to the end. But what he means by these two words, he afterwards explains of those who fail not, or become not wearied: for they, who being overcome as to patience, be broken down, must, by degrees, be necessarily weakened, and at length wholly fail.

James 1:5-8

5 If any of you lack wisdom, let him ask of God, that giveth to all men liberally, and upbraideth not; and it shall be given him.

5 Porro si quis autem vestrum destituitur sapientia, postulet a Deo, qui dat omnibus simpliciter, nec exprobrat; et dabitur ei.

6 But let him ask in faith, nothing wavering. For he that wavereth is like a wave of the sea driven with the wind and tossed.

6 Postulet autem in fide, nihil haesitans; nam qui haesitat similis est fluctui maris, qui a vento agitur et circumfertur.

7 For let not that man think that he shall receive any thing of the Lord.

7 non ergo existimet homo ille quod sit quicquam accepturus a Domino.

8 A double minded man is unstable in all his ways.

8 Vir duplici animo, instabilis est in omnibus viis suis.