An interesting quote I've read:
"My observation of Christendom is that most of us tend to base our relationship with God on our performance instead of on His grace. If we've performed well - whatever "well" is in our opinion - then we expect God to bless us. If we haven't done so well, our expectations are reduced accordingly. In this sense, we live by our works, rather than by grace. We are saved by grace, but we are living by the "sweat" of our own performance.
Moreover, we are always challenging ourselves and one another to "try harder." We seem to believe success in the Christian life (however we define success) is basically up to us: our commitment, our discipline, and our zeal, with some help from God along the way. We give lip service to the attitude of the Apostle Paul, "but by the grace of God I am what I am" (1 Cor. 15:10), but our unspoken motto is, "God helps those who help themselves." - Jerry Bridges