Albert Barnes Commentary James 1:3

"Knowing that the proving of your faith worketh patience." — James 1:3 (ASV)

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 it may cost to procure it. This is one of the passages that show James was acquainted with the writings of Paul. See the Introduction to James chapter 5, James 5:1. The sentiment expressed here is found in Romans 5:3. See Barnes on Romans 5:3.

Paul has carried the sentiment out further 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.