When he is come, he will reprove the world of sin, and of righteousness, and of judgment: of sin, because they believe not on me. John 16:8, 9.
The knowledge of the love of God as revealed in the plan of salvation will lead to the third step in coming to Christ, conviction of sin. The behaviorist defines sin in terms of transgression of the law, and it's true--that is the only legal, forensic definition for sin in the Bible. But there are some experiential definitions for sin in the Bible that go deeper than that. One of the best is in Roman 14:23: "Whatsoever is not of faith is sin." Whatever I do, if it isn't done through faith in Christ, it is sin.
There are two definitions for sin. One of them we will call the definition of sin, singular, and the other the definition for sins, plural. Sin is living a life without Christ. Sins are transgressions of the law. Living a life apart from Christ (sin) is the cause of doing wrong things (sins). It is interesting the way the King James Version reads on 1 John 3:4, "Whosoever committeth sin [who, as we say, lives a life apart from Christ] transgresses also the law."
When did Eve sin? When she ate the fruit? She sinned when she distrusted what God had told her and wandered away. Eating the fruit was simply the natural result of that. If I am having a problem with doing wrong things, my real problem is that I am living a life apart from Christ. Either that, or I haven't known Him long enough yet to grow to victory, and Jesus Himself allowed for growth.
So when we talk about conviction, we are talking about the realization that we are sinners, regardless of what we have done. Regardless of how good or bad we have been. We were born sinners, born sinful by nature. 1 John 5:17: "All unrighteousness is sin." Romans 3:10: "There is none righteous." So there is nobody righteous, we are all unrighteous, and all unrighteousness is sin. But don't ever feel that we are held responsible for being born in a world of sin. Jesus knows the way we were born, and the only thing we are responsible for is what we do with His plan of salvation.
When we face ourselves in the presence of Jesus, suddenly we are convicted that we are sinners. Not because of what we have done, but because of what we are. Through this conviction we realize our need of Him.