Another quote from the message by Thomas Watson entitled, The Godly Man's Picture Drawn with a Scripture Pencil
A godly man does not indulge himself in any sin. Though sin lives in him--yet he does not live in sin. A godly man may step into sin through infirmity--but he does not keep on that road.
What is it to indulge sin? To indulge sin is to give the breast to it and feed it. To indulge sin is to commit it with delight. The ungodly delight in wickedness (2 Thess. 2:12). In this sense, a godly man does not indulge sin. Though sin is in him--he is troubled at it and would gladly get rid of it.
There is as much difference between sin in the wicked, and sin in the godly--as between poison being in a serpent, and poison being in a man. Poison in a serpent is in its natural place and is delightful--but poison in a man's body is harmful and he uses antidotes to expel it. So sin in a wicked man is delightful, being in its natural place--but sin in a child of God is burdensome and he uses all means to expel it.
A godly man will not allow himself in secret sins. Some are more modest than to commit open gross sin. That would be a stain on their reputation. All will not sin on a balcony--but perhaps they will sin behind the curtain!
But a godly man dare not sin secretly, for he knows that God can neither be deceived by our subtlety, nor excluded by our secrecy. He knows that secret sins are in some sense worse than others. They reveal more deceit and atheism. He knows the secrets of every heart (Psalm 44:21).
But the curtain-sinner thinks that God does not see: . . . .hast thou seen what the ancients of the house of Israel do in the dark, every man in the chambers of his imagery? for they say, The LORD seeth us not; . . . . (Ezek. 8:12). How it provokes God, that men's atheism should give the lie to His omniscience! He that formed the eye--shall He not see? (Psalm 94:9).
A godly man knows that secret sins shall not escape God's justice. A judge on the bench cannot punish the treason of the heart. But the sins of the heart are as visible to God, as if they were written upon the forehead! As God will reward secret duties; so He will revenge secret sins!
A godly man enters his protest against sin: O wretched man that I am! who shall deliver me from the body of this death? (Romans 7:24). A child of God, while he commits sin, hates the sin he commits!