The Man Of Miracles (also known as M.o.M.) has offered Spawn his knowledge and guidance throughout his journeys in Greenworld, prophesying the upcoming Armageddon. (contorting Spawn's every move in his role at Armageddon)
The Man of Miracles powers are inconceivable, beyond the might of God and Satan. His true form, being the "Mother Of Existence" and yet, genderless.
It was revealed that Mother/Man Of Miracles was the one who once walked the earth known to man as "Jesus Christ" and that the "Twelve Disciples" (formed out of the souls of the Apostles) follow him as God.
Mother gave each of its immortal children a world to rule as they wished. God and Satan became Earth, and were in a consistent fight determining who becomes the ruler. Mankind was created by God, but given free will by Satan, and thus, Mother saw it as unique and acted on their behalf. M.o.M. then robbed Satan and God of their kingdoms and banished them to forgotten corners of the universe. He (appearing as a man) then came to earth as "Jesus Christ" to deliver a message of Love and Peace. (which was corrupted by mankind, and thus, Armageddon was inevitable)
Mother's appearance changes depending on the perception. He has appeared as a woman covered in Ivy (presumably Gaia), the Hindu goddess of vengeance (known as Kali), Jesus Christ and as the Mother Of Creation. He explains his constant change of appearance because reality is for more complex than the human mind can comprehend.