Having written yesterday about the one thing necessary in this life, John Owen applies a similar thought to the notion of hypocrisy from his book Spiritual-mindedness. Consider his words with sober minds and tender hearts, brothers and sisters.
Many have a false idea of hypocrisy. They think that a hypocrite is only one who pretends to be what he is not, and what he himself knows that he is not–or, at least, that he might easily come to know that he is not what he claims to be. That is true; but a hypocrite is also one who, under the light of the gospel, has professed faith in Christ and has received spiritual abilities, who prays, reads the Bible, and goes to church, yet continually and willingly fails to live wholeheartedly and sincerely to the glory of God, because he neglects one duty. This man is no less a hypocrite destined to eternal destruction than the other. Realising this may well make those who are lukewarm, cold, and lifeless in their love for Christ and spiritual things, examine themselves more seriously.
I do not mean that everyone who finds himself in a lukewarm state is a hypocrite. God forbid! I only say, that if this lukewarm state continues and there is no desire or effort made to repent of it, then it is a dangerous symptom of hypocrisy, and he who is wise and truly cares for his soul will not rest until he has searched his heart to its very depths to discover and root out this devilish hypocrisy.p. 208