We may observe the ingeniousness of the church in laying open her own state. It is the disposition of God’s people to be ingenious in opening their state to God, as in David, Nehemiah, Ezra, etc.
The reason is thus:
(1.) By a free and full confession we give God the honor of his wisdom in knowing of our own condition, secret and open. We give him the honor of mercy that will not take advantage against us, the honor of power and authority over us, if he should show his strength against us [in judgment]. We yield unto him the glory of all his chief prerogatives; whereupon Joshua moved Achan to a free confession, ‘My son, give gory to God,’ Joshua 7:19.
(2.) We shame Satan, who first takes away shame of sinning, and then takes away shame for sin. He tempts us not to be ashamed to do that we are ashamed to confess, so we, by silence, keep Satan’s council against our own souls. If we accuse ourselves, we put him out of office who is the ‘accuser of the brethren,’ Rev. 12:10.
(3.) We prevent, likewise, malicious imputations from the world. Augustine answered roundly and well when he was upbraided with the sins of his former age: ‘What thou,’ saith he, ‘findest fault with, I have condemned myself before.’
(4.) This ingenious dealing eases the soul, giving vent to the grief of it. While the arrow’s head sticks in the wound, it will not heal. Sin unconfessed is like a broken piece of rusty iron in the body. It must be gotten out, or else it will, by ranking and festering, cause more danger. It is like poison in the stomach, if it be not presently cast up it will infect the whole body. Is it not better to take shame to ourselves now, than to be shamed hereafter before angels, devils, and men?
– Richard Sibbes, Works 2:38-39