17: If any man defile the temple of God, him shall God destroy; for the temple of God is holy, which temple ye are.
18: Let no man deceive himself.  If any man among you seemeth to be wise in this world, let him become a fool, that he may be wise.

You deceive yourself whenever you believe something that is not true.  You wouldn't think that anyone would intentionally choose to believe a lie, but usually a person does it because for some reason the truth is not what they want to hear.  If you think you've attained wisdom in this world then he says here to become a fool so you can become wise.  The wisdom of God is not a common path, just as Jesus said it is a narrow gate that leads to life and few find it.  You find it through humility and a heart that sincerely seeks it.

As you desire to think like God thinks, according to His wisdom & ways then you will be protecting yourself from deception.  As a believer in Christ, you are a temple of God and you can draw from His Spirit within you to find the truth.

Confession: