If we never grow up, we will never be able to fend for ourselves.  The same goes for our spiritual growth. Hebrews 5:14 says, But solid food is for the mature, who by constant use have trained themselves to distinguish good from evil. The more mature we grow spiritually, the more we can distinguish the difference between right and wrong. When we are young we make simple mistakes, but as we grow older, we should not be making the same silly mistakes we made in our youth.