C.S. Lewis writes in Mere Christianity:
If you are a nice person – if virtue comes easily to you – beware! Much is expected from those to whom much is given. If you mistake for your own merits what are really God’s gifts to you through nature, and if you are contented with simply being nice, you are still a rebel: and all those gifts will only make your fall more terrible, your corruption more complicated, your bad example more disastrous. The Devil was an archangel once; his natural gifts were as far above yours as yours are above those of a chimpanzee.
A clever trap of the enemy is to get Christians to believe that they can be good on their own. Satan knows that humans are weak and frail in and of themselves and if they begin to rely on their own power, they will ultimately fall.
The problem is that we can go through the motions and fool a lot of people, but eventually our inner rebellion against God will be revealed.
It is not enough to merely follow the rules and make people happy. God wants more. He wants us to allow His Holy Spirit to empower and work through us so that we bring glory to Him.
The most clever trap of the devil is get us to think we are good — instead of realizing we are sinful and in need of grace. — Unknown Author
Devotional by Dr. James A. Scudder