What is the ruling on one who says: "The worshipper is corrupt"?

Prayer is a means of refining the soul and preventing corruption, and it cannot be described as a cause of corruption. However, if the praying person is indeed corrupt, committing forbidden acts and neglecting duties, and it is said of him, "The praying person is corrupt," meaning that his prayer did not prevent him from what it should have prevented him from, then there is no harm in that, though it is preferable to avoid this misleading phrase.