there could be many things that are spiritual unrighteousness, for example, the worship of any god, lord(christ) or spirit that is not the true One can bring "death"(deterioration) to the world (Exodus 20:3), the maintenance of heresies(unrighteous spiritual/religious theories/practices) can also bring "death" to the world (Exodus 20:4-6), the unrighteous use of the faith can also be a cause of "death" for many (Exodus 20:7), the spiritual/religious negation/negativization/satanization/demonization of creatures/creations of the true One can also bring "death" (Exodus 20:8-11), etc., and there could be all kinds of "death"(deterioration): spiritual deterioration, mental deterioration, intellectual deterioration, physical deterioration, economic deterioration, etc. as a result of the practice of unrighteous spirituality/religiosity/religion, because spiritual unrighteousness/lawlessness/wickedness (as it were) opens the door to the manifestation(s) of the "darkness" to the world...
Blessings