Here's what the Catechism says about the benefits for receiving communion:
What material food produces in our bodily life, Holy Communion wonderfully achieves in our spiritual life. Communion with the flesh of the risen Christ, a flesh "given life and giving life through the Holy Spirit," preserves, increases, and renews the life of grace received at Baptism. This growth in Christian life needs the nourishment of Eucharistic Communion, the bread for our pilgrimage until the moment of death, when it will be given to us as viaticum.
Jesus doesn't say that the soul and divinity of the food you eat passes into the latrine. If food is spiritual unclean, it's still not OK to eat, St. Paul says we shouldn't eat food sacrificed to idols, for pragmatic reasons - not reasons of our own spirituality, but because it looks bad to others.
It would be entirely Manichean for Catholics to believe that there is Good food and Bad food and they mean different things, bad food has no power it is nothing to us, Good food (and I'm using the word Good intentionally because no one is Good but God) is everything to us.
Holy Communion separates us from sin. The body of Christ we receive in Holy Communion is "given up for us," and the blood we drink "shed for the many for the forgiveness of sins." For this reason the Eucharist cannot unite us to Christ without at the same time cleansing us from past sins and preserving us from future sins:
For as often as we eat this bread and drink the cup, we proclaim the death of the Lord. If we proclaim the Lord's death, we proclaim the forgiveness of sins. If, as often as his blood is poured out, it is poured for the forgiveness of sins, I should always receive it, so that it may always forgive my sins. Because I always sin, I should always have a remedy.
That last part was from St. Ambrose, the Eucharist a remedy for sin. Some remedies are taken proactively, some are taken after the fact (after venial sins at least).
As bodily nourishment restores lost strength, so the Eucharist strengthens our charity, which tends to be weakened in daily life; and this living charity wipes away venial sins. By giving himself to us Christ revives our love and enables us to break our disordered attachments to creatures and root ourselves in him:
Your belief in Christ and His love doesn't go away when the Bread of the Eucharist is absorbed into your bloodstream.
Since Christ died for us out of love, when we celebrate the memorial of his death at the moment of sacrifice we ask that love may be granted to us by the coming of the Holy Spirit. We humbly pray that in the strength of this love by which Christ willed to die for us, we, by receiving the gift of the Holy Spirit, may be able to consider the world as crucified for us, and to be ourselves as crucified to the world. . . . Having received the gift of love, let us die to sin and live for God.
The Eucharistic celebration is a re-presentation of Christ on the cross, not just the Last Supper, the whole celebration is done in connection with the Cross. If it were the case that a remembrance of a celebration should be quashed then Jesus ought to have turned the tables over at the Wedding at Cana instead of miraculously making wine.
Maybe this addresses your question, but St. Paul says you have to receive worthily
Whoever, therefore, eats the bread or drinks the cup of the Lord in an unworthy manner will be guilty of profaning the body and blood of the Lord. Let a man examine himself, and so eat of the bread and drink of the cup. For anyone who eats and drinks without discerning the body eats and drinks judgment upon himself. That is why many of you are weak and ill, and some have died
1 Cor 11:27-30
First, we need faith in Jesus’s true presence in the Eucharist. The Eucharist is not a symbol. It is the body and blood of Jesus that he offers us to enter into communion with him.
You don't "enter into communion" with a chicken sandwich. You have to believe that the Eucharist is what Jesus says "my Body".
Second, we also need to remove obstacles to receiving the grace of Jesus’s presence. If we are in a state of serious, mortal sin, we are not able or ready to enter into the communion that Jesus offers us
You must be in a state of grace to receive Communion in the Catholic Church.