And the result of God’s gracious gift is very different from the result of that one man’s sin. For Adam’s sin led to condemnation, but God’s free gift leads to our being made right with God, even though we are guilty of many sins. -Romans 5:16

This is the wonder of wonders. The Christian is positively not guilty any longer the moment he believes. Now, if Her Majesty in her goodness spares a murderer by giving him a free pardon, that man cannot be punished: but still he will be a guilty man; she may give him a thousand pardons, and the law cannot touch him, but still he will be guilty; the crime will always be on his head, and he will be branded as a murderer as long as he lives. But the Christian is not only delivered from the bondage and from the punishment, but he is positively absolved from the guilt. Now this is something at which you will stand amazed. You say, “What? is a Christian no more a sinner in God’s sight ?” I answer, he is a sinner as considered in himself; but in the person of Christ he is no more a sinner than the angel Gabriel; for snowy as are angelic wings, and spotless as are cherubic robes, an angel cannot be more pure than the poor blood-washed sinner when he is made whiter than snow. Do you understand how it is that the very guilt of the sinner is taken away? Here I stand to-day a guilty and condemned traitor; Christ comes for my salvation, He bids me leave my cell, “I will stand where you are; I will be your substitute; I will be the sinner; all your guilt is to be imputed to Me; I will die for it, I will suffer for it; I will have your sins.” Then stripping Himself of His robes, He says, “There, put them on; you shall be considered as if you were Christ; you shall be the righteous one. I will take your place, you take Mine.” Then He casts around me a glorious robe of perfect righteousness; and when I behold it, I exclaim, “Strangely, my soul, art thou arrayed, with my elder brother’s garments on.” Jesus Christ’s crown is on my head, His spotless robes are round my loins, and His golden sandals are the shoes of my feet. And now is there any sin? The sin is on Christ; the righteousness is on me. ~C.H. Spurgeon

http://www.blueletterbible.org/Comm/spurgeon_charles/sermons/0009.cfm