In Revelation, God uses symbols He established throughout Scripture to communicate the necessity of Jesus' atoning death on the cross for our sins.
If we reject all that Jesus offered to us, his body (bread) his blood (wine), his payment for our sin by taking the wrath of the Father upon Himself, then we'll have to pay for those things ourselves... our own body will be crushed, our own blood spilled, and we must face the wrath of God.
His death on the cross spares us this terrible fate!