Adam Clarke on James 2:22

Seest thou how faith wrought - Here is a proof that faith cannot exist without being active in works of righteousness. His faith in God would have been of no avail to him, had it not been manifested by works; for by works - by his obedience to the commands of God, his faith was made perfect - it dictated obedience, he obeyed; and thus faith ετελειωθη, had its consummation. Even true faith will soon die, if its possessor do not live in the spirit of obedience.