More wisdom from Thomas Watson:

“Confession purges out sin. Augustine called it “the expeller of vice”. Sin is bad blood; confession is like the opening of a vein to let it out. Confession is like the dung-gate, through which all the filth of the city was carried forth (Neh. 3:13). Confession is like pumping at the leak; it lets out that sin which would otherwise drown. Confession is the sponge which wipes the spots from off the soul.”

More on confession:

“It reproves those who are so far from confessing sin, that they boldly plead for it. Instead of having tears to lament it, they use arguments to defend it. If their sin is anger, they will justify it: “I do well to be angry!” (Jon. 4:9). If it be covetousness, they will vindicate it. When men commit sin they are the devil’s servants; when they plead for it they are the devil’s attorneys, and he will give them a fee.”