One could make a case that the Synoptics are good for Orthodox Christians. However, I do make special claim to GosMark as it is the earliest and most mystical of the lot with very few explicit OT allusions (and there allegedly is a Secret Gospel of Mark floating around, not yet discovered, at least according to Clement of Alexandria.) GosMatt and GosLuke certainly rely on the OT for much of their support (perhaps inline with Justin Martyr’s belief that the history should be interwoven.) The two tie Jesus’ birth to OT scripture, that he was born in Bethlehem; GosMark and GosJohn do not!
Mark, like John, has Jesus born in Galilee. Matthew and Luke tie it to OT prophesy. I believe they were completely incorrect. GosMatt overtly has Jesus born in Bethlehem; GosLuke has Mary & Joseph from Galilee but temporarily in Bethlehem for the census, during which time Jesus’ birth took place. As we know, Christ’s Spirit did not enter Jesus until his baptism, making this whole escapade superfluous.
Per Rudolf Steiner’s First Lecture from True Knowledge of the Christ: Theosophy & Rosicrucianism — The Gospel of John, this excerpt really rings loudly: “As our theologians are also materialistically minded, the three Gospels of the three Synoptists suit them better [that is Mark, Matthew, and Luke,] for with them, materialistic exegesis is permissible. It goes against the grain in materialistic thinking [which he discusses is pervasive in today’s society] to accept a Spirit that is vastly superior to all humanity. It is more to their taste to see Jesus of Nazareth as a noble individual, the ‘simple man’ from Nazareth. In The Gospel of John it is quite impermissible to see in Jesus only the principles which are also to be found in any other human being. The soul of the Christ in the body of Jesus is something completely different. The Gospel of John shows us the Christ not only as an outstanding human being but also as a Spirit that embraces the whole earth.”
Furthermore, for Orthodox Christians, ApJohn would be a redaction of the OT and not an omission, if it would even be relevant or appropriate. In fact, one could see a case that ApJohn was a heterodox positioning paper to those of other religions, though I do not believe this aspect defines the primary purpose of this treatise—that would be unification with Christ and the Father in the Pleroma via the Autogenes / Spirit of Light process. The reality is that Christ’s Father is so much better than Yaltabaoth, and by monumental proportions. However, the Christian Orthodoxy (led by those the Valentinians referred to as Sophia’s psychics) chose to keep Yaltabaoth around by including the Old Testament in the Canon—with multiple explicit references to the Hebrew Bible found in GosLuke and GosMatt.