Whereas guilt is related to unresolved transgression, false guilt is based on false accusations or a misunderstanding.
As the, "accuser of the brethren," Satan imposes false guilt in order to rob believers of victory. This can come through personal misunderstandings, or sincere (but errant) friends and family, or from judgmental critics, or false doctrines.
False guilt enslaves, weakens, confuses. Sinning religion imposes false guilt without offering deliverance from sin's penalty and power, and pollution.
God is specific when He convicts of sin, but Satan gives groundless guilt feelings based on human standards, rather than God's revelation.