You said"One of the great things about our God is that he doesn't ask us to change before we come to him. He asks us to come to him so he can change us. He also doesn't ask us to wait until we are changed before we can be used to serve him. If God chooses to change me some day, he is free to do so, he knows I'm open to that possibility. But I do not believe God wants me to sit around doing nothing while I wait for him to change me."

You have to change to come to the Lord.
First and foremost in your heart.

Your heart changes towards sin, you do not want to sin.

And then you repent.

You repent of your sins, and turn from them.
You must change to see your sins and repent from the heart.

You cannot exist in sin and in the Lord.