You need to become a Holy, clean and pure vessel to hold Jesus Christ. You cannot serve satan & Jesus. They will not live together in you. You must choose. In Confession, your soul is purified, and filled with God’s Grace & goodness. You prepare a place of perfect harmony where Jesus can abide in you, and you abide in Him. You are unified with God & every member of His body, the Church. Together you are MIGHTY!
When you choose to commit mortal sin it changes “who” you are drastically. Choosing mortal sin over God, makes you an enemy of Jesus Christ, and robs your soul of God’s grace.
Communion is intimately receiving Jesus Christ into your body. It is like the sexual union of a Married couple. Would you hire prostitutes to come to your house, and have sex with them in front of your wife, and then expect her to be welcoming & have sex with you too? No! That would so damage your love relationship that she would most likely divorce you. It would ruin your marriage. That is what Mortal sin does to your relationship with God. You proclaim, “God, I choose this sin over you, cause you don’t know what is best for my life, and my soul. I believe satan’s way is better! I am following satan not the God of all creation!”
When you approach Jesus in the Eucharist you are saying that you live in harmony with Jesus Christ, and that you are sharing an intimate union with Him. You are saying that you have prepared your soul to be filled with God’s Grace!