Maxwell was known for his mathematical success in formulating the theory of classical electromagnetism. But without the help of Maxwell’s angel, he could never have succeeded. His guardian angel is called the displacement current. It restores the underlying space-time symmetry inherent in Maxwell’s four partial differential equations and thus asserted the reversibility of all electromagnetic processes, implying that a moving divine photon without interaction can live forever. On the other hand, as one of the founders of the kinetic theory of gases, Maxwell had tried in vain invoking the Maxwell’s demon to stop the inevitable increase of thermodynamic entropy, making all irreversible processes reversible; which can prevent the eventual heat death of the universe at maximum entropy and absolute zero of temperature. If Maxwell’s demon does appear and fulfill this universal deed then this space-time entity can never be a demon nevermore and matter will coexist with pure energy lasting forever in ageless multiverses.