Peace with God comes by being justified by faith Rom 5:1 "Therefore being justified by faith, we have peace with God through our Lord Jesus Christ:"
Peace with God is based on a work done for us and that is the work of Christ on the Cross: His death, burial, and resurrection. That is the Gospel of the Grace of God, Rom 4:16 "Therefore it is of faith, that it might be by grace; to the end the promise might be sure to all the seed; not to that only which is of the law, but to that also which is of the faith of Abraham; who is the father of us all," It is faith alone in Christ alone by which you are saved. A person that is saved is of the faith of Christ. In other words, he is saved by what Christ did on the cross and it is faith in Christ plus nothing.
Abraham believed God - Just faith plus nothing, Rom 4:21 "And being fully persuaded that, what he had promised, he was able also to perform." Abraham's faith was imputed to him for righteousness, Rom 4:22 "And therefore it was imputed to him for righteousness."
Now look at 4:23,24 "Now it was not written for his sake alone, that it was imputed to him;" Rom 4:24 "But for us also, to whom it shall be imputed, if we believe on him that raised up Jesus our Lord from the dead;"
Your faith is imputed to you for righteousness when you believe , Rom 4:24 "But for us also, to whom it shall be imputed, if we believe on him that raised up Jesus our Lord from the dead;" Rom 4:25 "Who was delivered for our offences, and was raised again for our justification." In these two verses, you have the death burial and resurrection of Christ. "Therefore being justified by faith, we have peace with God through our Lord Jesus Christ:"
"......justified by faith" Faith in what? What God did for you in Christ. Rom 4:24 But for us also, to whom it shall be imputed, if we believe on him that raised up Jesus our Lord from the dead; Rom 4:25 Who was delivered for our offences, and was raised again for our justification: that is what the Love of God means for you, that is why Christ came, that is what Christ did for you. That is a finished work - You are reconciled to God -2Co 5:18a And all things are of God, who hath reconciled us to himself by Jesus Christ,...." 2Co 5:19 a To wit, that God was in Christ, reconciling the world unto himself, not imputing their trespasses unto them; ..."
God has reconciled you - He has brought you near - What is left is for you is to believe on Him for what He did. Rom 5:1 Therefore being justified by faith, we have peace with God through our Lord Jesus Christ: