Romans 14:5-6

One person judges one day to be more important than another day. Someone else judges every day to be the same. Let each one be fully convinced in his own mind. Whoever observes the day, observes it for the honor of the Lord. Whoever eats, eats for the Lord, since he gives thanks to God; and whoever does not eat, it is for the Lord that he does not eat it, and he gives thanks to God.