The prayer offered in faith will restore the one who is sick: This saying is generally true, depending on God's will. Only prayers with genuine faith will receive a positive response from the Lord. Faith for healing is a gift from God (See also Mark 9:23; John 14:13–14; 15:7, 16; 16:23–27; 1 John 3:22; 5:14–15).
If he has sinned: James suggests that some illnesses might result from sin. It is important to confess and seek forgiveness for the sin (James 5:16; see Mark 2:3–12; John 5:14).