5:16 Confess your faults. “Faults” is a different word than “sins” in James 5:15, which primarily refers to “offenses” or “trespasses.” It is used either for offenses against God or against fellow men. The latter are evidently meant here, for the admonition here is to confess such offenses to the individual person or persons we have offended. Once the offenses are confessed, then it is fitting to pray for whatever healing is needed.
5:16 fervent. “Effectual fervent” is one word in the Greek (energeo), meaning “energizing.” The one praying such an energizing prayer (therefore, healing prayer) is assumed to be “righteous,” both in standing before God through faith in Christ, and in practice before God, having left no sins of his own unconfessed and made right.