'Conviction' in the Bible
When the rulers and Council members had threatened them further, they let them go, finding no way to punish them because [of their fear] of the people, for they were all praising and glorifying and honoring God for what had happened;
while the Apostles with great force of conviction delivered their testimony as to the resurrection of the Lord Jesus; and great grace was upon them all.
His advice carried conviction. So they called the Apostles in, and--after flogging them--ordered them not to speak in the name of Jesus, and then let them go.
[Philip said to him, “If you believe with all your heart, you may.” And he replied, “I do believe that Jesus Christ is the Son of God.”]
and He made no distinction between us and them, cleansing their hearts by faith [in Jesus].
because He has set a day when He will judge the inhabited world in righteousness by a Man whom He has appointed and destined for that task, and He has provided credible proof to everyone by raising Him from the dead.”
Paul said, “John performed a baptism of repentance, continually telling the people to believe in Him who was coming after him, that is, [to confidently accept and joyfully believe] in Jesus [the Messiah and Savior].”
Afterwards he went into the synagogue. There for three months he continued to preach fearlessly, explaining in words which carried conviction the truths which concern the Kingdom of God.