ISB ~ James 5 v20

brings back a sinner:Fraternal correction is a work of mercy that is sometimes awkward but is urgently necessary for one who has strayed from the truth (Gal 6:1). The language of “turning back” signifies repentance both in the OT (Hos 6:1; Joel 2:12) and in the NT (Lk 1:16; Acts 3:19).

his soul:i.e., the soul of a person who has formerly gone astray but has come to repentance.

cover a multitude of sins:Perhaps an allusion to Prov 10:12 (similar wording appears in 1 Pet 4:8). The notion of “covering” sins is a Hebrew idiom for forgiveness (Neh 4:5; Ps 32:1).