Interfaith debates tend to artificially restrict the range of options. Depending on who we’re debating, we have rotating opponents. In inter-Protestant debates, the Anabaptist tradition is frequently generally sidelined, which isn’t fair.
In Catholic/Evangelical debates, Eastern Orthodoxy is generally sidelined. Also, a Catholic apologist will try sof-tpeddle intra-Catholic debates involving dissidents on both far left and far right ends of the spectrum.
In Catholic/Orthodox, or Evangelical/Orthodox debates, the Oriental Orthodox churches are generally sidelined.
This selectivity arbitrarily limits the range of actual options, leaving the misleading impression that there are only two sides to every debate, so that if we knock out our immediate opponent, then we win by default. But the options are more diverse.
Take Eastern Orthodoxy. For convenience, we may refer to The Orthodox Church in the singular. But, of course, there is no such thing as The Orthodox Church. It never existed.
What we have, instead, is a loose affiliation of autocephalous churches that share some historical and theological commonalities. But being national churches, they have also branched out over time, undergoing varying degrees of internal development and dissension.
As a result, you have both intra-Orthodox and inter-Orthodox dissensions. Who speaks for Greek Orthodoxy? Cyril of Alexandria or Theodore of Mopsuestia? Doesn’t Constantinople outrank Alexandria?
Who speaks for Russian Orthodoxy? The Old Believers? The hierarchy under the Bolsheviks? Or the expatriate church?
Going back the Oriental Orthodox, in Evangelical/Orthodox debates this tradition is generally ignored because Evangelicals are ordinarily opposed to Monophysitism, and so the Oriental Orthodox are summarily excluded.
But this is misleading, and gives the Eastern Orthodox an unfair advantage. And that’s because Evangelicals don’t necessarily oppose Monophysitism for same reasons as the Eastern Orthodox. We oppose it because it’s unscriptural.
But the Eastern Orthodox oppose it because it’s contra-conciliar. And that, in turn, is bound up with a high-church polity and apostolic succession.
Yet if you grant high-church assumptions, then the Oriental Orthodox have just as good or poor a claim to apostolic succession as the Eastern Orthodox. So we shouldn’t be giving the Eastern Orthodox a free pass on this issue. They need to fight and win on more than one front. They need to beat the Oriental Orthodox at their own game before they’re in any position to mount an attack on Evangelicalism, or some particular tradition thereof.
They also need to explain who speaks for Eastern Orthodox, and why.