As Christians, we do not have to try to change. When we come to Christ, he changes us immediately. Ezekiel 36:26 says, “And I will give you a new heart, and a new spirit I will put within you. And I will remove the heart of stone from your flesh and give you a heart of flesh.” Our problem sometimes is that we choose to see ourselves as we once were. We choose to define ourselves by our sin and not who we are in Christ. There is a big difference between saying I have a bad temper than saying I am a Christian who struggles with the temptation to anger. The former says there is no hope to change, the latter says through Christ, I can overcome.
As Christians, we are new creations in Christ. We need to see ourselves in Christ and not in our sin. We should all be able to say, I may not be who I ought to be, nor am I what I will be, but thank God I am not who I used to be.