What do you have to "repent of" in order to become a Christian?

Repent of everything! What do I enjoy that I have not made an idol out of? What day have I made it through without the vilest lust creeping into my head? How many lies have I told? How many people have I hated? Remember, Christ said whoever wants to follow him must deny himself, and then take up his cross. To deny yourself is to refuse to have anything to do with the sinner you were, and to embrace Christ's atoning work in faith. Repentance is a complete and total turning away from that which is offensive to a holy God.