Of all the evidences of the real work of the Spirit, a habit of hearty private prayer is one of the most satisfactory that can be named. A man may preach from false motives. A man may write books and make fine speeches and seem diligent in good works, and yet be a Judas Iscariot. But a man seldom goes into his closet, and pours out his soul before God in secret, unless he is serious.
J.C. Ryle