It takes a priest in Confession to remit the effects of mortal sin, but Confession is not necessary to remit venial sin.
However, confessing venial sins is a good idea, since the graces conferred in Confession help fight against those sins which were confessed.
I'm just SURE this is in the bible; somewhere; Right?
The blood of Jesus is somehow insufficient to cleanse from all sins??
The Catholic God is a very stingy god who doles out little packets of grace based on the performance of His subjects.
Fortunately the God of Scripture, who calls ALL men to Himself, LAVISHES His grace out on us freely and without restriction through Jesus Christ, who dwells in the lives of His children.
Ephesians 1:3-10 Blessed be the God and Father of our Lord Jesus Christ, who has blessed us in Christ with every spiritual blessing in the heavenly places, even as he chose us in him before the foundation of the world, that we should be holy and blameless before him. In love he predestined us for adoption as sons through Jesus Christ, according to the purpose of his will, to the praise of his glorious grace, with which he has blessed us in the Beloved. In him we have redemption through his blood, the forgiveness of our trespasses, according to the riches of his grace, which he lavished upon us, in all wisdom and insight making known to us the mystery of his will, according to his purpose, which he set forth in Christ as a plan for the fullness of time, to unite all things in him, things in heaven and things on earth.
Romans 5:1-2 Therefore, since we have been justified by faith, we have peace with God through our Lord Jesus Christ. Through him we have also obtained access by faith into this grace in which we stand, and we rejoice in hope of the glory of God.
John 1:14-17 And the Word became flesh and dwelt among us, and we have seen his glory, glory as of the only Son from the Father, full of grace and truth. (John bore witness about him, and cried out, “This was he of whom I said, ‘He who comes after me ranks before me, because he was before me.’”) For from his fullness we have all received, grace upon grace. For the law was given through Moses; grace and truth came through Jesus Christ.