Here is what Saint Paul said:
1 Corinthians 11:27-31
Douay-Rheims 1899 American Edition (DRA)
Therefore whosoever shall eat this bread, or drink the chalice of the Lord unworthily, shall be guilty of the body and of the blood of the Lord. But let a man prove himself: and so let him eat of that bread, and drink of the chalice. For he that eateth and drinketh unworthily, eateth and drinketh judgment to himself, not discerning the body of the Lord. Therefore are there many inform and weak among you, and many sleep. But if we would judge ourselves, we should not be judged.
The King James Version is even more severe in its language:
1 Corinthians 11:27-31
King James Version (KJV)
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. For this cause many are weak and sickly among you, and many sleep. For if we would judge ourselves, we should not be judged.
Note to real presence deniers: One does not eat and drink damnation unto himself for unworthily partaking of a symbol.