God can’t use self-righteous people for holy things. It’s not that He doesn’t want to, but when a person believes their sanctification and righteousness comes from their knowledge of a set of “rules” and their own efforts to obey them (like what the Pharisees thought and taught) they become useless to God.

Are you righteous? If so, how would you explain to someone else what makes you righteous? And what about your life would indicate to God that you want to be used by Him for Holy use?