The explanations given above seem to me reasonable and possible; they are enough, I think, to remove the _necessity_ for assuming a lost document, but perhaps not quite enough to destroy the greater probability.

This conclusion, we shall find, will be confirmed when we pass from considering the substance of Justin's Gospel to its form.
But now if we ask ourselves _what_ was this hypothetical lost document, all we can say is, I believe, that the suggestions hitherto offered are insufficient.

The Gospels according to the Hebrews or according to Peter and the Protevangelium of James have been most in favour.

The Gospel according to the Hebrews in the form in which it was used by the Nazarenes contained the fire upon Jordan, and as used by the Ebionites it had also the voice, 'This day have I begotten Thee.' Credner [Endnote 110:1], and after him Hilgenfeld [Endnote 110:2], thought that the Gospel according to Peter was used.

But we know next to nothing about this Gospel, except that it was nearly related to the Gospel according to the Hebrews, that it made the 'brethren of the Lord' sons of Joseph by a former wife, that it was found by Serapion in the churches of his diocese, Rhossus in Cilicia, that its use was at first permitted but afterwards forbidden, as it was found to favour Docetism, and that its contents were in the main orthodox though in some respects perverted [Endnote 110:3].