If they take Holy Communion while they’re still in love with their sins, it doesn’t bring them the fruit of salvation.
People aren’t satisfied with Holy Communion unless they really hunger for it. Unless they’re hungry. Those who’ve realized through their bad habits, that sin is poverty and hunger. These are the people who take the full energy and grace and efficacy.
Not even the so-called elect are exempt from this rule. Because it’s not possible even for them (the so-called elect) to be without sin, since they will certainly commit something of a sinful nature unless they force themselves, every day, to avoid even those minor transgressions with which our backsliding human nature will forever be sullied.
When people aren’t careful to conquer their imperfections every day, then, however much they imagine that the transgressions they commit are really not so serious, their souls gradually fill up with sins. Then they lose the fruit of that inner state which we call spiritual riches, because it fills us with spiritual joy.
“Saint Gregory the Theologian”