The Sacrament of the Altar
Q63. Who receives this sacrament worthily?
Fasting and bodily preparation are certainly fine outward training. But that person is truly worthy and well prepared who has faith in these words: "Given and shed for you for the forgiveness of sins." But anyone who does not believe these words or doubts them is unworthy and unprepared, for the words "for you" require all hearts to believe.
Scripture Proofs — King James Version
1 Corinthians 11:27–29
“Wherefore whosoever shall eat this bread, and drink this cup of the Lord, unworthily, shall be guilty of the body and blood of the Lord. But let a man examine himself, and so let him eat of that bread, and drink of that cup. For he that eateth and drinketh unworthily, eateth and drinketh damnation to himself, not discerning the Lord’s body.”
Hebrews 11:6
“But without faith impossible to please : for he that cometh to God must believe that he is, and he is a rewarder of them that diligently seek him.”
2 Corinthians 13:5
“Examine yourselves, whether ye be in the faith; prove your own selves. Know ye not your own selves, how that Jesus Christ is in you, except ye be reprobates?”
Read Luther’s expanded teaching
From the Large Catechism (1529)