I have been exploring joining the Orthodox Church. I understand that a reverence and honor for the Theotokos is not a bad thing. If it was good enough for the archangel at the annunciation, it should be good enough for us. That said - I was wondering how the Orthodox Church explains the lack of veneration for Mary in the NT Epistles?
In addition to the Annunciation accounts in Luke, we might also consider Luke 11:27-28, where Jesus declares his mother blessed not because she is His mother, but rather because she heard the will of God and carried it out. Likewise the examples of His obedience to her as a child and at the Wedding of Cana (Luke 2:51, John 2:3-10) and His care for her even near the moment of His death (John 19:26-27).
I think your specific question is answered by the broader question of why not everything taught in the Gospels seems to be discussed in the Epistles of the New Testament.
Within the Orthodox faith, the Gospels are seen as central to the entire Bible. The Gospels, wrote Archbishop Averky Taushev:
comprise the very essence of the law of God's new covenant with mankind, for they show us the salvific events of Jesus Christ's life and His divine teaching.1
"Everything we need to know for our salvation," one Orthodox priest I know states during almost every sermon, "is contained in the Gospels."
The Epistles, on the other hand, are an "interpretation of the teachings of Christ, as applicable to various situations in life."2 Father Lawrence Farley writes of the Epistles:
The epistles witness to this corporate reality, and give examples of how Christian life is lived out in this body. We do not need a divine rule book outlining what to do in every conceivable situation. For that day to day direction we have the guidance of the Holy Spirit. The epistles give us something more valuable than a book of instructions. They give us models, glimpses of life, slices of apostolic reality to taste and feed upon. If we didn’t have the Holy Spirit, no doubt a comprehensive rule book thundering away would be helpful. But since we do have the Holy Spirit, the epistles fit our need precisely.
Also relevant here, I think, is the fact that each Epistle in the New Testament addressed some specific set of issues that were causing conflicts for believers. Paul wrote the Romans to help them understand how they should relate to Jews and non-Christians; he wrote to the Corinthians largely to address divisions within the community and address immoral behavior; he wrote the Galatians because they were backsliding back into Judaistic practices; etc. We might conclude that since nothing seems to be written regarding how one should be respecting Mary (who was probably still alive at the time), then apparently no one was going around insulting her, claiming she wasn't a virgin, etc.
The Epistles are not viewed within the Orthodox Church - I think it is correct to say - as some corpus of dogma that needs to be appended to the Gospels (along with Acts and Revelation) to create a sort of comprehensive manual of systematic theology. In the Orthodox view, this turns the Bible into a kind of pseudo-Koran.
1.The Four Gospels, p.xiv