You cannot get better if you already think you are the best.
It has been said that "Good is the enemy of Great." Often times you become accomplished at something, you become satisfied and comfortable, perhaps too comfortable. When was the last time you consciously tried to improve as a Christian? Are you one of those "good" Christians feeling pretty "good" about yourself or are you striving to find ways to serve Him better?
The reward for humility and fear of the LORD is riches and honor and life.