One who has not confessed one’s sin is like someone who has not been baptised. It is impossible to find salvation.
If anyone confesses before one dies, even if one has never received the Holy Communion, he must carry on believing in salvation.
However, if one did not confess, even though one has received the Holy Communion many times before, one not only would not receive anything but also one would also deserve to receive the Holy Communion.
Vae victis!
One must first confess one’s sins and then receive the Holy Communion. First, we wash and clean the vessel and then we pour in the precious liquid.
Saint Cosmas of Aetolia