HCSB Rom 14:5 One person considers one day to be above another day. Someone else considers every day to be the same. Each one must be fully convinced in his own mind. 6 Whoever observes the day, observes it to the Lord. Whoever eats, eats to the Lord, since he gives thanks to God; and whoever does not eat, it is to the Lord that he does not eat, yet he thanks God. 7 For none of us lives to himself, and no one dies to himself. 8 If we live, we live to the Lord; and if we die, we die to the Lord. Therefore, whether we live or die, we belong to the Lord.
21 It is a noble thing not to eat meat, or drink wine, or do anything that makes your brother stumble. 22 Do you have faith? Keep it to yourself before God. Blessed is the man who does not condemn himself by what he approves. 23 But whoever doubts stands condemned if he eats, because his eating is not from faith, and everything that is not from faith is sin.This last line is often paired with Romans 10:17 ("faith cometh by hearing, and hearing by the word of God") to conclude that anything we do in a religious sense must be authorized by the written Word of God, but I believe that's mixing two different "faith" definitions. The Romans 10:17 faith is a faith that brings us into a saved relationship with Jesus; the Romans 14:23 faith is a confidence that we are not condemning ourselves by what we approve (v. 22), specifically in the realm of disputable matters such as eating of certain meets or observing certain holidays, etc, which Paul plainly states is okay either way so long as it's done in honor of the Lord.
HCSB Luke 2:10 But the angel said to them, "Don't be afraid, for look, I proclaim to you good news of great joy that will be for all the people: 11 today a Savior, who is Messiah the Lord, was born for you in the city of David. 12 This will be the sign for you: you will find a baby wrapped snugly in cloth and lying in a manger."