I found another verse about following the straight and narrow path. It's Psalm 32:8. God says, "I will instruct you and teach you in the way that you should go. I will counsel you and watch over you." then he adds, "Do not be like the horse or mule which have no understanding but must be controlled by a bit and bridel or they will not come to you." God has given us free will. He will direct us in the way that we should go if we will look to him and let him guide us. A horse is impatient and would run ahead of his master so a bit has to hold him back. A mule is complacent and would often sit still if its master didn't tug and pull on his face to make him move. God does not want to do either of these. he wants us to choose to follow him. He says, "if you love me, you will follow my commandments. That is how I know that you love me." And not only following his morality commandments,He says also that "Anything that is not done by faith is sin." Romans 14:23. Faithfully follow his path without swerving or getting ahead of Him like a horse or lagging behind him like some old mule.
When we do get selfish though, and choose to love ourselves more than we love Christ (represented by the swerving on my map from the previous post). He gives us comforting scripture like All of Psalm 32 which is about forgiveness and Psalm 51 which is about renewal. And He reminds us, Psalm 103:12, "as far as the east is from the west, so far has he removed our transgressions from us." (Also a very cool song by Casting Crowns.)