In combating the heresies of the Manichaean Docetists and Apollinarians, we should not be surprised to find Didymus insisting on the fullness of the human nature of Christ. He concludes there must be two natures united in Christ, not speculating on precisely how these work together but restricting himself to the expression "a single Christ." In his atonement theory, Didymus does not mention deification, but rather focuses on the ransom and the restoration of the image and the likeness. The fragmentary nature of his writing at this point does not allow us to draw definite conclusions, but he does speak of "universal salvation." Jerome, probably correctly, accused Didymus of confessing the ultimate restoration of the devil.