'Vindication' in the Bible

My meaning is that Christ has become a servant to the people of Israel in vindication of God's truthfulness-- in showing how sure are the promises made to our forefathers--

And He will also confirm you to the end [keeping you strong and free of any accusation, so that you will be] blameless and beyond reproach in the day [of the return] of our Lord Jesus Christ.

This is my defense to those who would put me on trial and interrogate me [concerning my authority as an apostle]:

For behold what earnestness this very thing, this godly sorrow, has produced in you: what vindication of yourselves, what indignation, what fear, what longing, what zeal, what avenging of wrong! In everything you demonstrated yourselves to be innocent in the matter.