408. What is confession? Confession is the of our sins to an authorized priest for the purpose of obtaining . 409. Why must we confess our sins? We must confess our sins because Jesus Christ us to do so in these words, spoken to the and to their successors in the priesthood: "Whose sins you shall forgive, they are forgiven them; and whose sins you shall retain, they are retained." 410. How do these words of Christ oblige us to confess our sins? These words of Christ oblige us to confess our sins because the cannot know whether he should forgive or retain our sins unless we them to him. 411. Is it necessary to confess every sin? It is necessary to confess every sin which has not yet been confessed and forgiven; it is not necessary to confess our sins, but it is better to do so. 412. What are the chief qualities of a good confession? The chief qualities of a good confession are three: it must be , sincere, and . 413. When is our confession humble? Our confession is humble when we ourselves of our sins with a conviction of for having offended God. 414. When is our confession sincere? Our confession is sincere when we tell our sins and frankly. 415. When is our confession entire? Our confession is entire when we confess at least our mortal sins, telling their kind, the of times we have committed each sin, and any changing their nature. 416. What are we to do if without our fault we forget to confess a mortal sin? If without our fault we forget to confess a mortal sin, we receive Holy Communion, because we have made a confession and the sin is forgiven; but we must tell the sin in confession if it again comes to our . 417. What happens if we knowingly conceal a mortal sin in confession? If we knowingly conceal a mortal sin in confession, the sins we confess are forgiven; moreover, we commit a mortal sin of . 418. What must a person do who has knowingly concealed a mortal sin in confession? A person who has knowingly concealed a mortal sin in confession must confess that he has made a confession, tell the sin he has concealed, mention the he has received since that time, and all the mortal sins he has committed since his last good confession.