from Edmund Schlink's Theology of the Lutheran Confessions (p. 177):
"If faith as trusting reception constitutes worthiness, then worthiness does not consist in the act of receiving but in the treasure received, not in faith as a human act but in faith as in him who is believed."
"At all events, nothing is required of man in the sacrament that God does not himself give to man in the sacrament. That is to say, here God only gives and he requires nothing. Since the Lord's Supper requires faith and gives faith, it is altogether a gift. We need add nothing to God's grace. We need merely accept and receive his gift. It is literally placed into our mouth."