Thematic Bible: Those that doubt

Therefore, whatever you believe about this matter should be held between you and God. That person is happy who does not condemn himself for practicing something he believes is right. But the person who has doubts about eating [a certain food] is self-condemned if he [goes ahead and] eats it, because his action is not based on faith [i.e., if he lacks the conviction that he is doing what is right]. And whatever is not done with such a conviction is a sin.