'Confirm' in the Bible

For I say that the Messiah became a servant of the circumcised on behalf of God’s truth, to confirm the promises to the fathers,

He will also strengthen you to the end, so that you will be blameless in the day of our Lord Jesus Christ.

Therefore I urge you to reaffirm your love to him.

Therefore, brothers, make every effort to confirm your calling and election, because if you do these things you will never stumble.