'Convinced' in the Bible

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.

I know and am convinced [as one] in the Lord Jesus that nothing is unclean [ritually defiled, and unholy] in itself; but [nonetheless] it is unclean to anyone who thinks it is unclean.