Romans 2:19
2:19 and if you are convinced that you yourself are a guide to the blind, a light to those who are in darkness,
Romans 8:38
8:38 For I am convinced that neither death, nor life, nor angels, nor heavenly rulers, nor things that are present, nor things to come, nor powers,
Romans 14:5
14:5 One person regards one day holier than other days, and another regards them all alike. Each must be fully convinced in his own mind.
Romans 14:14
14:14 I know and am convinced in the Lord Jesus that there is nothing unclean in itself; still, it is unclean to the one who considers it unclean.