Christ is a substitute for everything, but nothing is a substitute for Christ.
Christianity is Christ!
It is not only that sin consists in doing evil, but in not doing the good that we know.
God is looking for broken men who have judged themselves in the light of the cross of Christ. When He wants anything done, He takes up men who have come to the end of themselves, whose confidence is not in themselves, but in God.
No one who really wants to count for God can afford to play at Christianity.
If what they are saying about you is true, mend your ways. If it isn't true, forget it, and go on and serve the Lord.