New Defender's Study Bible Notes
5:15 faith shall save. “Save” here means “deliver”—that is, from his illness.
5:15 sick. “Sick” in this verse is different from both “afflicted” in James 5:13 and “sick” in James 5:14. Used elsewhere only in Hebrews 12:3 and Revelation 2:3, it means “wearied.” In context, it must refer to the depression induced by the guilt of his sin. This can only be relieved, not by some psychiatric encouragement of his supposed self-worth, but by repentant confession of his specific sin to God (I John 1:9), then to the church and its elders. The latter can then pray for him in faith (note that the latter prayer is their prayer, not his—they must have the faith to believe God’s promise). If all conditions are met, then “the Lord shall raise him up.” Notice that nothing in the context mentions the need for someone with the gift of healing, though one or more of the elders (at least in apostolic times, before the completion of the New Testament) may well have had such a gift (to be used, however, in evangelizing, rather than in a case such as the one described here). The reason why this type of healing does not occur more often today is probably because one or more of the conditions are not met.
5:15 if. “If” here means “since.” The reason for the illness in such a case is unconfessed sin that has injured the church and its ministry. If the conditions have been met for healing, they will also have been met for forgiveness.