Remember that the only way to get to this meal is through the door. The door is your baptism. Only those who are in Christ can eat this meal which is Christ. But your baptism into Christ is not just the bare fact that you got wet; your baptism is that by the grace of God, your dead heart was quickened, and by faith you trusted in Christ to be your redemption, righteousness, and sanctification.
Saying that the door to this table is the door of baptism is just another way of saying Jesus is the way, the truth, the life (John 14:6). Jesus is the door. Jesus is the only way to come to this table.
If you try to go around the door, climbing over the walls of self-righteousness, you will come to a table. But the bread you eat will be the bread of judgment, and the wine you drink will be the wine of the fierceness of God’s wrath.
But if you come by faith through the door of Jesus, God looks at you and sees Jesus. Your sin is left out on the porch. Christ carries you to your place at this table, and feeds you with His body. So enter the door by faith. Eat this meal by faith. And remember that from the first to the last, it is Christ who won your salvation, Christ who feeds you this bread of life: His own eternal life.
So come in faith, and welcome to Jesus…