'Convinced' in the Bible

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

One person regards one day above another, another regards every day alike. Each person must be fully convinced in his own mind.

I know and am convinced in the Lord Jesus that nothing is unclean in itself; but to him who thinks anything to be unclean, to him it is unclean.

And concerning you, my brethren, I myself also am convinced that you yourselves are full of goodness, filled with all knowledge and able also to admonish one another.