According to Promise full audiobook by Charles Spurgeon.
Charles Spurgeon challenges each of us to examine our own heart to make sure our faith is solidly grounded, to count the cost, and to experience the promise of grace. “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. The life of God within the soul creates an infinite difference between the man who has it and the man who has it not; and the point is, to make sure that we have this life. I desire to help my reader in the business of self-examination. I would have him go further than examination, and attain to such abundance of grace that his holy and happy state shall become a witness to himself. No man can lose by honestly searching his own heart.”