Then he took a cup, gave thanks, and gave it to them, and they all drank from it. He said to them, "This is my blood of the covenant, which will be shed for many. Mk 14: 23-24
Jesus wasn't kidding when he described the Cup of Salvation as "my blood of the covenant,". He wasn't saying 'this represents' or 'this is just like' or 'this is sort of the same thing as ....you know... it's sort of like my blood but it really isn't it just kinda is important in an esoteric sort of way.'
Jesus didn't say that. Jesus doesn't lie. He said "IS". If you don't accept that then don't lead music for mass. Does that mean you have to have perfect faith to lead music? No. None of us have perfect faith anyway. That's why we require God's grace. We can however, accept the teaching for what it is and not change it to fit our ability to understand. Especially for communion. Communion is the paramount object of the mass. In no other instance in our lives do we come closer to God than at communion. I think my favorite teachings of Christ center around these teachings and also his discourse regarding salvation in Jn. chapter 6. Especially "As a result of this, many [of] his disciples returned to their former way of life and no longer accompanied him." We have so many people who love Jesus but for some reason refuse to accept his teaching regarding the Bread of Life and the Cup of Salvation. I pray that some day all people will be able to accept communion for what it is and then we will all "call upon the name of the Lord".
Psalm 116: I Will Take the Cup of Salvation