I have heard some Christians say, "I'm OK. Jesus has done everything on the Cross!" And yes, that is true-judicially. But that is not the end of the story. It is just the beginning. When you became a Christian, God provided everything for you in Jesus Christ. When you received Jesus as your Lord and Saviour, His Holy Spirit immediately came into your spirit, and that is how you were born again. So your spirit is OK. No need to be worried about that. But, as I said, that is the beginning of the story.