This is a meal, and we know that we are to wash up for meals. It is the same with this sacramental meal as it is with any meal. Before you eat, you wash up. That is just what you do.
We understand this by how we place our time of confession at the beginning of the service and the meal at the end of it. We wash up first, and then we eat.
But we want to make sure we truly understand how this “washing up” actually works. When the Lord instituted the Supper, this is one of the things He taught on. When the Lord had come to wash Peter’s feet, Peter naturally objected. It was not fitting that the Lord take the position of a slave. After a brief exchange, the Lord said this: “He that is washed needeth not save to wash his feet, but is clean every whit: and ye are clean, but not all. For he knew who should betray him; therefore said he, Ye are not all clean” (John 13:10–11).
Jesus has not yet washed Peter’s feet, but He says that Peter was already clean (and the others also, Judas only excepted). This clearly means that the foot-washing was a metaphor for what might be called the incidental cleansing of sanctification, and not the foundational cleansing of justification. Judas was wrong at the root, but the others were true followers of Christ.
Peter and the others were clean, the Lord said. He said this, despite knowing and predicting that they would all be scattered shortly. Peter’s betrayal is just hours in the future . . . and yet he was declared to be clean.
When you confess your sins at the beginning of the service, you are not accomplishing the actual cleansing that is necessary. You are rather testifying to the fact that you know that Christ is the only one who cleanses. And you, having been justified by faith alone, have been declared clean.
So come, and welcome, to Jesus Christ.