Romans 14:5
Also, some make a difference between one day and another; others esteem every day alike. Let each one be fully persuaded in his own soul.
Romans 14:23
And he that makes a difference is condemned if he eats, because he does not eat by faith; and whatsoever is not out of faith is sin.
Romans 14:14
I know and trust in the Lord Jesus that for his sake there is nothing unclean, but to him that esteems any thing to be unclean, to him it is unclean.
1 Corinthians 8:7
Howbeit there is not in everyone that knowledge, for some with conscience of the idol unto now, eat it as a thing offered unto an idol, and their conscience being weak is defiled.
1 Corinthians 8:11
and through thy knowledge the weak brother shall perish, for whom Christ died.
Galatians 4:9-10
But now, having known God, or rather being known of God, how do ye turn again to the weak and beggarly elements, in which ye desire again to be in slavery?
Colossians 2:16-17
Let no one therefore judge you in food or in drink or in respect of a feast day or of the new moon or of the sabbath days,
1 John 3:19-21
And in this we know that we are of the truth and have our hearts certified before him.