'Declare' in the Bible

Whom God hath set forth to be a propitiation through faith in his blood, to declare his righteousness for the remission of sins that are past, through the forbearance of God;

To declare, I say, at this time his righteousness: that he might be just, and the justifier of him which believeth in Jesus.

yes, also of nations; since one is God who shall declare righteous the circumcision by faith, and the uncircumcision through the faith.

when I declare that I have deep grief and unceasing anguish of heart.

If you declare with your mouth that Jesus is Lord, and believe in your heart that God raised him from the dead, you will be saved.