This really is the beginning point of any real relationship with God. Our first response to His powerful work of making us alive inside, of Him giving us that new heart of flesh, of Him regenerating us, is this changed attitude towards ourselves and towards our sin and rebellion. The natural man, if he is confronted with anything wrong in his behavior at all, will respond with defensiveness and self-justification. The key word/idea is "but"... it goes along this line: "yes, that was bad, but it's not my fault... he, you, they, it made me..."; or "you can't understand, I was provoked"; or this classic "he had it coming, you should see what he did before"; or topping the charts "you don't have the right to judge me! Who are you to decide what I can and can't do?!" All of these thinly veiled things, these weak excuses add up to one core idea... "I was right in what I did, my only real problem was getting caught..."
This pattern of self-righteousness, of self-centered reasoning is NOT repentance, even if we swear to never let it happen again. The only way that we can ever really repent is if our thinking is radically altered. We must begin to see the world from a different perspective... from a perspective which says that God is right in all He says, does, commands and requires, period. No excuses, no alterations, no "if"s, "and"s or "but"s. The response of a living soul, when it sees its own sin, is to "loathe" itself for its deeds. To hate the reality of our sin so much, that we literally hate ourselves is where we begin to see the world aright. Because no matter what the culture tells us, or the media, or our friends and especially no matter what we tell ourselves, there is NEVER any excuse for sin. Understanding and submitting to this fact is good evidence that regeneration has, in fact, occurred. God tells us that He will make us His own people and the proof of that change is found in the transformation of rebels into sons. Oh beloved, if you hate your sin, rejoice in seeing it thus, for it is good evidence that you are not what you once were! If, instead, the facts of this truth make you angry, then fall on your face before Almighty God and beg for mercy before its too late!