Teshuvah for Thought and Teshuvah for Deed

The Rama, zt”l, explains why an olah is completely burned up, while a sin-offering is eaten partially by the kohanim. “The chatas is eaten by the kohanim since a chatas is brought to atone for a sin. It is only through enduring this embarrassment that the sinner will do a true teshuvah. It is obvious why the sinner himself may not partake of the korban: how can he have any benefit from his sin? Surely this would show that he does not take his failing seriously.
“Another reason why kohanim would eat the korban was to supply those who serve Hashem with food, since this too atones for sin. Although it comes to atone for a sin, a korban chatas is still kodshei kodashim. This is to show that in the place which ba’alei teshuvah stand, even a complete tzaddik cannot stand. If this man’s teshuvah was complete, no man can stand where he stands. A korban olah is kodshei kodashim for the same reason.
“But when an olah comes to atone, it is completely consumed. An olah is not eaten by the kohanim since it comes to atone merely for thoughts in one’s heart. Because the sin was not revealed, it does not require the embarrassment of the kohanim publicly partaking of the flesh of the korban. Korbanos which do not atone yet are kodshei kodashim are brought by those who are on a high level of wholeness and are themselves kodesh kodashim.”