For if the blood of goats and bulls, and the sprinkling of defiled persons with the ashes of a heifer, sanctify for the purification of the flesh...
Hebrews 9:13

There are different kinds of righteousness, holiness, purity, clean, unclean, etc., and different processes for achieving each. The existence of one doesn't negate others, but it's important not to get them confused. There was never an animal sacrifice that can eternally remove the guilt of sin from your soul.