Romans 14:2-6

One person has faith that he may eat all things, but the one who is weak eats only vegetables.

The one who eats is not to regard with contempt the one who does not eat, and the one who does not eat is not to judge the one who eats, for God has accepted him.

Who are you to judge the servant of another? To his own master he stands or falls; and he will stand, for the Lord is able to make him stand.

One person values one day over another, another values every day the same. Each person must be fully convinced in his own mind.

The one who observes the day, observes it for the Lord, and the one who eats, does so with regard to the Lord, for he gives thanks to God; and the one who does not eat, it is for the Lord that he does not eat, and he gives thanks to God.