Only enemies can be reconciled. Thus God’s message of reconciliation takes us back to Adam, the father of the human race, who first rebelled against God, and explains why God must deal with us all on the same level, as sinners who need salvation.
In Romans 5:12, we read: “…By one man sin entered into the world, and death by sin; and so death passed upon all men, for that all have sinned”.
Thank God, though, the message of reconciliation is not concerned exclusively with the “one man” by whom sin entered into the world. Indeed, it is chiefly concerned with the “one Mediator between God and men, the Man Christ Jesus” (I Tim. 2:5).
“Therefore as by the offence of one, judgment came upon all men unto condemnation; even so by the righteousness of one, the free gift [of salvation] came upon all men to justification of life. For as by one man’s disobedience many were made sinners, so by the obedience of one shall many be made righteous” (Rom. 5:18,19).
It is by this other “one Man” and His death on Calvary, then, that sinners may be reconciled to a holy God. In Colossians 1:21,22, Paul, the Apostle of reconciliation, writes to believers:
“And you, that were once alienated and enemies in your mind by wicked works, yet now hath He reconciled, In the body of His flesh, through death, to present you holy and unblameable and unreproveable in His sight.”
Thus “when we were enemies, we were reconciled to God by the death of His Son” (Rom.5:10). And thus, too, the Apostle pleads: “We pray you in Christ’s stead, be ye reconciled to God. For He hath made Him to be sin for us, [Christ] who knew no sin; that we might be made the righteousness of God in Him” (II Cor. 5:20,21). source