The “Secret Book of James” or the “Apocryphon of James” from the Nag Hammadi text (Nag Hammadi Codex 1/2 = Meyer, M. (ed.) The Nag Hammadi Scriptures, 2007, hereafter NHS 23-30) says that it is “a secret book” that was “revealed” to James by the “Master,” meaning Jesus, with instructions “to be careful not to communicate too many people this book” (NHS 23). James also speaks of “another secret book that the savior revealed to me” which had earlier sent his reader (NHS 24).
The “Secret Book of James” begins with a narrative of a Christophany of the resurrected Jesus to Peter and James 550 days after his resurrection (NHS 24). Five hundred and fifty days is a year and 185 days, or a little more than a year and a half. Since the resurrection occurred at Passover, which is in late March or early April, this Christophany occurred in late September or early October, in other words at the High Holy days and the Day of Atonement on the day in which the High Priest is to enter the Holy of Holies. This is surely not coincidental.
There is also some possible deification language in the “Secret Book of James.” When Christ appears to James and Peter, he offers to take them “to the place from which I came” (NHS 24). In a general sense this is heaven, but in the context of the Day of Atonement, it is quite likely that it is a reference to the celestial Temple, where Christ serves as the Great High Priest. This interpretation is confirmed later in the text when Christ says that he “ shall ascend to the place from which I have come” where he can “listen to the hymns that await me in heaven,” and where “I must take my place at the right hand of my Father” (NHS 29). Thus, when James is invited to go to the place from which Christ came, he is invited to the throne of God and the celestial temple. This concept is dramatically illustrated by the statement that “Blessed is he who has seen himself as a fourth one in heaven” (NHS 28). The three in Heaven are obviously the Father, the Son, and the Holy Spirit, with the “fourth one in heaven” being James, or more generally anyone who participates in a celestial ascent. Thus, if James is to go to the place from which Christ has come, and become a “fourth one in heaven, it implies the deification of James.
With Christ’s revelation complete, he says that “a chariot of spirit” will “carry me out” to where he shall “strip myself that I may clothe myself” (NHS 30). The chariot of the spirit here is an obvious allusion to Elijah, Enoch, and Ezekiel (2 Kgs 2; 1 Enoch 70; Ezek 1, 10). When Christ says that he will strip himself so that he may clothe himself it is possible that he is referring to a celestial transfiguration in which he sheds his mortal form and assumes celestial glory. On the other hand, it is quite possibly also an allusion to the Day of Atonement ritual in which the High Priest shed his robes, was purified, and donned new robes in order to enter into the Holy of Holies (Lev 16.23-24; Sirach 50.11; Mishnah, Yoma 7.5).
James and Peter then follow Christ in a mystical ascent to heaven, where they hear trumpet blasts, a probable allusion to the Feast of Trumpets associated with the Day of Atonement. In heaven they join with the angels in singing hymns and rejoicing, thus participating with the angelic priests in the celestial temple rituals. However, they were not allowed at this time to see God enthroned in the celestial Holy of Holies. Upon returning from their celestial ascent, James and Peter tell the other apostles that Christ “gave us his right hand, and promised all of us [eternal] life.” In other words, their celestial ascent culminated in a covenant of eternal life symbolized by Christ shaking their right hand. When his vision is complete, James “went up to [the temple] in Jerusalem to pray (NHS 30).