Ya'akov 5:20

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.