Every once in a while, I hear someone say, "I don't drink the wine at Mass" or something similar. Please remember that we consume the Blood of Christ, not wine. This is fundamentality important.
After the consecration, something incredible happens to what was bread and wine. Even referencing to the cup as the Blood of Christ is not quite adequate. We believe that Christ is present whole and entire in what we receive at communion. We believe this because of Jesus, the words we use at the consecration at Mass come from our Lord.
The Eucharist is the source and summit of the Christian life. "In the most blessed sacrament of the Eucharist the body and blood together with the soul and divinity, of our Lord Jesus Christ and, therefore, the whole Christ is truly, really and substantially contained."
Catechism of the Catholic Church 1374. "The principal fruit of receiving the Eucharist in Holy Communion is an intimate union with Christ Jesus."
CCC 1391, "Anyone who desires to receive Jesus Christ in Eucharistic communion must be in the state of grace.“
CCC 1415, “Anyone aware of having sinned mortally must not receive communion without having received absolution in the sacrament of penance."
Take this all of you and drink from it for this is the chalice of my blood Take this all of you and eat of it for this is my body Do this in memory of me.