The one who turns him back leads him again to God and, consequently, returns him to life in union with God, the source of life. In this way he saves his soul from death.
"He will cover a multitude of sins." Compare Prov 10:12; 1 Pet 4:8. Again, the sins of the one who went astray and was converted are meant.
By being turned to the true path, joined with repentance, the one converted will receive from God the forgiveness of all the sins he committed during his turning away from the truth.
Since, when one turns away from the truth, one's whole manner of activity is sinful, the one who has turned away inevitably has a multitude of sins.
God's forgiveness of this multitude of sins is expressed by the words, "he will cover a multitude of sins."
The one who turns him back covers the sins of the one converted, since the conversion was accomplished through the mediation of the converter.
The very work of covering sins is ascribed to him, on the presupposition that the converted person would not have turned back without the one who converted him.
With this exhortation to the most important work of Christian love, the conversion of those who stray, the loving apostle concludes his loving epistle.