A somewhat unfortunate phrasing.
2 Cor is not really on point. We aren't talking about a believer and a non-believer. Presumably, the priest is someone who believes, but commits gross sins anyway. Is your salvation null and void if the preacher who gave the altar call was an axe murderer? No. Because the "sacrament" is between you and God.... and God chose to use a sinner to give the call.
Jesus chose Judas to set into motion His own death on the cross. The fact that the same cross is responsible for your salvation is not removed because Judas was a sinner - and he walked with Christ daily.
That is our presumption.
The rest of the "saved" gang here are judging the priest's soul based upon their superior knowledge. That and the fact that no saved person ever struggles with habitual sin.
The fear of the Lord is the beginning of wisdom, no?
SD