2 Nephi 9:16-17

16 And assuredly, as the Lord liveth, for the Lord God hath spoken it, and it is his eternal word, which cannot pass away, that they who are righteous shall be righteous still, and they who are filthy shall be filthy still; wherefore, they who are filthy are the devil and his angels; and they shall go away into everlasting fire, prepared for them; and their torment is as a lake of fire and brimstone, whose flame ascendeth up forever and ever and has no end.

17 O the greatness and the justice of our God! For he executeth all his words, and they have gone forth out of his mouth, and his law must be fulfilled.