Faith isn't fixing your sin.

Faith is letting God worry about all that.

Example:
You realize you sin, every day, and that sinners go to hell.

You can

A) Protect yourself. Ask for forgiveness everyday. Really show you are trying your best. Spend time doing what ever you think please God.

or

B) No longer must atonement for your sins be made every year. (And no, Jesus did not substitute in the place of animal sacrifice, asking for forgiveness. Honestly a sacrifice once a year, sounds much easier than daily asking!)

You read that Jesus was the final sacrifice for our sins. And, for some reason you believe that. So, you don't worry about being right with God. Instead you go through life with God as your friend, and when death comes... there is no fear.

For you know your friend, who has been with you, will catch your soul in His hands, and bring you home.