'Convinced' in the Bible

and being fully convinced that what he had promised, he was also able to do.

For I am convinced that neither death, nor life, nor angels, nor rulers, nor things present, nor things to come, nor powers,

One person prefers [one] day over [another] day, and another person regards every day [alike]. Each one must be fully convinced in his own mind.

I know and am convinced in the Lord Jesus that nothing [is] unclean of itself, except to the one who considers something to be unclean; to that person [it is] unclean.

Now I myself also am convinced about you, my brothers, that [you] yourselves also are full of goodness, filled with all knowledge, able also to instruct one another.