Therefore being justified by faith, we have peace with God through our Lord Jesus Christ. (Romans 5:1)
The Bible mentions several kinds of peace. First, there's world peace. Well, my friend, as long as there is sin in the hearts of men, there never will be peace in the world - not until the Prince of Peace comes. Christ will bring peace on this earth. But world peace is not the kind of peace that Paul is talking about here.
Then there is that peace which is known as tranquility of soul. That is the peace to which the Lord Jesus referred when He said to His disciples, "Peace I leave with you, my peace I give unto you: not as the world giveth, give I unto you ..." (John 14:27). This is a peace that comes to certain believers who have trusted Christ and who are resting in Him and who are doing His will. I wish I could say that I experience this peace all the time. I do not. I suppose I am like most believers in that I have up and down experiences. However, Paul is not referring to the peace of personal tranquility.
Then there is a third kind of peace which Paul mentions to the Philippian believers - "the peace that passeth all understanding" (see Philippians 4:7). Well, since it passes all understanding, I certainly don't know what it is, and I have a notion that you don't know either. The peace Paul is talking about, which he lists as the first benefit of salvation, is "peace with God through our Lord Jesus Christ." This is the peace that comes to the soul of one who has trusted Christ as Savior and knows that God no longer has any charge against him, that he is no longer guilty. He knows that God, who had to be against him in the past, is now for him. He knows that he has a salvation that is permanent and eternal. This is the peace that comes because of sins forgiven and because everything is right between you and God. You will notice that Paul mentions again and again that we have peace through the blood of Jesus Christ, which means that everything is all right between our soul and God. That is wonderful peace!
This was explained to me by a wonderful pastor when I was a young boy in my teens. He said that when man sinned in the Garden of Eden, not only did man run away from God - and found himself alienated from the life of God, with no capacity for God and no inclination to turn to Him - but God also had to turn away from man. Then when Christ died on the cross, God turned around, so that now a holy God can say to a lost sinner, "Come." His arms are outstretched. He says, "Come unto me, all ye that labour and are heavy laden, and I will rest you" (Matthew 11:28, literal translation mine). This is peace, the rest of redemption.
My friend, God is reconciled. You don't have to do anything to reconcile Him, as we have seen. A great many people think that you have to shed tears to reconcile God. You don't need tears to soften the heart of God! You don't have to do anything. Because Christ died on the cross, God is reconciled today. The message of the gospel is, "Be ye reconciled to God." The next move is yours. When you accept His salvation, then you experience peace that your sins have been forgiven.