Romans 14:5-9 (NKJV)
5 One person esteems one day above another; another esteems every day alike. Let each be fully convinced in his own mind. 6 He who observes the day, observes it to the Lord; [a]and he who does not observe the day, to the Lord he does not observe it. He who eats, eats to the Lord, for he gives God thanks; and he who does not eat, to the Lord he does not eat, and gives God thanks. 7 For none of us lives to himself, and no one dies to himself. 8 For if we live, we live to the Lord; and if we die, we die to the Lord. Therefore, whether we live or die, we are the Lord’s. 9 For to this end Christ died [b]and rose and lived again, that He might be Lord of both the dead and the living.