As the followers of Christ evolved from a group that was largely Jewish in the first decades to a movement that was largely Gentile, numerous changes occurred. Some of these changes were necessary and healthy, while others brought with them catastrophic consequences. Seismic theological consequences took place as the increasingly Gentile church abandoned both its historical understanding of and theological roots in the Jewish Scriptures.
By the phrase “theological roots in the Jewish Scriptures” I am NOT referring to the frequent Christian practice of cherry picking the Old Testament. This classic Christian cherry picking includes finding the Old Testament useful to argue for capital punishment, certain views of creation, dieting, lyrics for Christian hymns, Vacation Bible School stories, and predictions of Jesus. The early church’s appreciation for the Jewish Scriptures was far more profound than mere cherry picking; there is not a chapter in Revelation that does not rely upon imagery and themes from the Jewish Scriptures.
Scholars have at times questioned whether early congregations of believers knew the sayings of Jesus and the narrative materials that would eventually be used to write the four canonical Gospels. Whatever one thinks about that issue, that question cannot really be a valid concern for John and his congregations in Roman Asia. It is very clear from contemporary Christian writings such as the Didache and 1 Clement, not too mention the book of Revelation itself, that the words and deeds of Jesus were known by congregations by the end of the 1st century AD.
One of the many, many examples of the influence of Old Testament imagery and theology in Revelation is seen in the Christophany of Revelation 1 when “one like a son of man” is revealed to John (Rev. 1:12-16). The fact that this scene resonates so clearly with images from Daniel is all the more significant since the Christophany might have consisted of images of Jesus from the Gospels. Why not reveal Jesus in terms of the imagery in the Synoptic Gospels or the Fourth Gospel, like modern Gentile Christianity typically does?
John and those in his congregations lived in a spiritual climate where often their first thoughts about God and his work in this world through Jesus the Messiah were formulated in terms of vibrant Old Testament imagery and theology. John’s writing makes it abundantly clear that he would have rejected, in fact he did reject, any notion of congregations of Christ that understood God, God’s Anointed One, and God’s people in this world apart from a robust reliance upon and continuation of major themes from the Old Testament. Admittedly this is an oversimplification (and subject to misunderstanding as all oversimplifications are), but it seems to me that John would have chosen to be a “Biblical Christian” rather than a cherry picking “New Testament Christian.” In this regard John would have been out of step with most forms of modern Christianity, East or West, Protestant, Catholic, or Orthodox.
I cannot know for sure whether John had ever read 2 Timothy, but the book of Revelation, including the Christophany of 1:12-16, surely demonstrates what it can look like when a Christian leader uses “the sacred writings that are able to instruct you for salvation through faith in Christ Jesus” and employs them “for teaching, for reproof, for correction, and for training in righteousness, so that everyone who belongs to God may be proficient, equipped for every good work” (2 Tim. 3:15-17).