If Secret Mark is Authentic ... Then Christians Can't Marry

This is clearly the same text that Clement shares with the Marcionites and other heretics who reject marriage.  The reader just has to think about the implications of the material:

And going near, Jesus rolled away the stone from the door of the tomb. And straightaway, going in where the youth was, he stretched forth his hand and raised him, seizing his hand ... and after six days Jesus told him what to do, and in the evening the youth comes to him ... and he remained with him that night, for Jesus taught him the mystery of the Kingdom of God. And thence, having arisen (ἀναστὰς), he returned to the other side of the Jordan.

The mystery rite is the resurrection and clearly according to Clement the basis for the Alexandrian baptism rite so "after the resurrection (μετὰ τὴν ἀνάστασιν)," he says, "they do not marry and are not given in marriage." (Clement Stromata 3.47.1)  And then, making clear that his opponents who share some non-canonical gospel understood themselves to have gone through 'the resurrection' mentioned in that gospel, Clement adds "If, as they claim, they have already partook in the resurrection (τὴν ἀνάστασιν ἀπειλήφασιν) ..." (ibid 3.48.1).  And again, "Similarly, they cite the dictum "The children of this age do not marry and are not given in marriage." But if anyone ponders over this answer about the resurrection of the dead, he will find that the Lord is not rejecting marriage, but is purging the expectation of physical desire in the resurrection." (ibid 3.87.1,2)

How did Clement's Gospel of Mark narrative confirm that the initiate who had undergone the mystery of the kingdom of God could not marry?  The act is hinted at in the words "after six days Jesus told him what to do, and in the evening the youth comes to him" and confirmed in the image of the 'purified one' (Zacchaeus) sitting in the branch of sycamore tree, a fruit from the tree of life.

"Zacchaeus as fruit; the fruit of its own nature it gave not, but it yielded one rational fruit!" [Ephrem On the Nativity]

"Zacchaeus in the sycamore is, so to say, a new fruit of a new age" Ambrose on Luke 19.15]