A lot of people seem to think that when we become Christians we make this gigantic leap from being one person into being a completely new person.
In Gods eyes we do change immediately from the "old man" (as the Bible would say) to the "new man." But becoming like Jesus is not something thats done overnight; its a process that we live by taking one little step after another.
We can do that, cant we? We can take another little step past the first, and then another little one, and another... And these little steps may not seem like much at the time, but when you look back you see progress big progress!
God doesnt expect you to run the mile in four minutes, but he promises to give you the strength to keep going the distance until you finish the course and receive your reward because you have kept the faith. Thats good news!