It would be very difficult to say how far a man may go in religion, and yet die in his sins; how much he may look like an heir of heaven, and yet be a child of wrath. Many unconverted men have a belief which is similar to faith, and yet it is not true faith. Certain persons exhibit pious affections which have the warmth of spiritual love, but are quite destitute of gracious life.
--Charles H. Spurgeon
According to Promise, p. 5