James 1:3 - Albert Barnes' Notes on the Bible

Knowing this, that the trying of your faith worketh patience - Patience is one of the fruits of such a trial, and the grace of patience is worth the trial which it may cost to procure it. This is one of the passages which show that James was acquainted with the writings of Paul. See the Introduction, Section 5. The sentiment expressed here is found in Romans 5:3. See the notes at that verse. Paul has carried the sentiment out farther, and shows that tribulation produces other effects than patience. James only asks that patience may have its perfect work, supposing that every Christian grace is implied in this.