ἔνδειξις

God presented Him as an atoning sacrifice in His blood through faith, in order to demonstrate His righteousness, because in His forbearance He had passed over the sins committed beforehand.

He did this to demonstrate His righteousness at the present time, so as to be just and to justify the one who has faith in Jesus.

In full view of the churches, then, show these men the proof of your love and the reason for our boasting about you.

…without being frightened in any way by those who oppose you. This is a clear sign of their destruction but of your salvation, and it is from God.