JAS 5:20

20 You should have da'as that the one having helped a choteh [(sinner)] to become a ba'al teshuva and to turn from the toyus [(error)] of his derech, and from setiyah HaDerech Hashem[(turning aside or deviating from the Way of Hashem)], will save the neshamah of him from mavet and will cover a multitude of chatta'im.