The writer speaks of a person's conscience as if it were an object that could be made better and better until it was without fault. A person's conscience is his knowledge of right and wrong. It is also his awareness of whether or not he has done wrong. If he knows he has done wrong, we say that he feels guilty. Alternate translation: "are not able to make the worshiper free from guilt" (See: [[rc://en/ta/man/jit/figs-metaphor]])
The writer appears to refer to only one worshiper, but he means all those who go to worship God at the tabernacle. (See: [[rc://en/ta/man/jit/figs-genericnoun]])