Romans 14:1-5

As for the one whose faith is weak, accept him [into your fellowship], but not for [the purpose of] quarreling over his opinions. One man’s faith permits him to eat everything, while the weak believer eats only vegetables [to avoid eating ritually unclean meat or something previously considered unclean]. The one who eats [everything] is not to look down on the one who does not eat, and the one who does not eat must not criticize or pass judgment on the one who eats [everything], for God has accepted him. Who are you to judge the servant of another? Before his own master he stands [approved] or falls [out of favor]. And he [who serves the Master—the Lord] will stand, for the Lord is able to make him stand. One person regards one day as better [or more important] than another, while another regards every day [the same as any other]. Let everyone be fully convinced (assured, satisfied) in his own mind.