What do I mean when I say "Our God is defiled and guity"? Or to put it another way, "Jesus needed cleansing from sin"? I mean that on the cross, our sins were both legally and morally transferred to Jesus, Whom God punished mercilessly. His blood thereby cleansed Himself from our sins.
This is the doctrine of "expiation": that is, our sins are removed from us and placed upon Jesus by divine decree. Meditate on that last sentence: your sins are completely, permanently removed! Your history is cleared! Every sin, from the smallest lie to the grossest deceit, from a lustful look to adultery, from drunkenness to bribery, from pride to sorcery, is removed forever.
Now we come to a crucial point: Jesus did not simply endure legal punishment for sins he had never committed. This would have been indeed unjust of the Father to punish the Son without cause. Rather, He endured the just wrath for our sins which now truly stained His soul. In expiation, God did not simply remove our sin, he transferred it to His Beloved Son. God defiled Himself voluntarily.
This has long been the teaching of the church, but is there a biblical text which proves this expiation? Look at 2 Corinthians 5:21: "For our sake he made him to be sin who knew no sin, so that in him we might become the righteousness of God." Jesus, the Holy Son of God, became sin during His crucifixion so that we might become righteousness itself.
What practical effect should this doctrine have upon our lives? First, never fear punishment for sin. If you follow Jesus, you may have faith that God transferred all your transgressions to Jesus, then punished them, so they are gone forever. One way to think about it is that God, by divine miracle, changed history so that every sin you've ever committed was actually done by Jesus. Forget what lies behind and press onward in full assurance of your cleansing!
Second, If you have not believed on Jesus or turned to follow Him, then these promises do not apply to you yet. Yet they are open to all who turn to Jesus. "Look to Him, all you ends of the earth and be saved!" If you want the cleansing of which I've written, talk to a pastor as soon as you can. Ask them how you can be saved.
Third, know the greatness of God's love for you. We can say that God loves you more than He hates sin, because He was willing to let the guilt and shame of sin rest upon Himself rather than punish you.
Fourth, hate sin. Think upon the effect of your sin, not only upon yourself and other humans, but upon your Lord. Will you heap more shame, guilt, and dishonor upon your King? You can not call Jesus your Lord and yet continue to do those things which He hates and which He bore in Himself.
Last, when we inevitably sin and feel defeated and shameful, we can find relief and hope in the truth that Jesus knows those feelings to the utmost. We unholy creatures do feel great shame for our sin, especially after we become Christians, yet Jesus, the great Creator truly knew the depth of evil and iniquity which stained Him upon the cross. Find strength in the thought that Jesus knows what you're going through. Sin will kill you by depression if you do not realize that Jesus knows your pain and will dwell with you and strengthen you.