'Conviction' in the Bible

You have not for the second time acquired the consciousness of being--a consciousness which fills you with terror. But you have acquired a deep inward conviction of having been adopted as sons--a conviction which prompts us to cry aloud, "Abba! our Father!"

As for the faith you do have, have it as your own conviction before God. How blessed is the person who has no reason to condemn himself because of what he approves!

But he who is uncertain [about eating a particular thing] is condemned if he eats, because he is not acting from faith. Whatever is not from faith is sin [whatever is done with doubt is sinful].