James 1:2-4 in the King James Version reads:
2 My brethren, count it all joy when ye fall into divers temptations; 3 Knowing this, that the trying of your faith worketh patience. 4 But let patience have her perfect work, that ye may be perfect and entire, wanting nothing.
These verses open the epistle of James, addressing his readers about trials and patience. Read it in context at James 1:2-4, or the full chapter at James 1.