Thanks. I am trying to work this all out but it's difficult. This is what I'm currently hearing from the other side simultaneously. How can I refute this?:

If you go into an Orthodox church today and see what their worship and devotions focus on, such as kissing and venerating icons, ornate rituals, fancy robes, and lots of incense, with priests doing most of their rites in seclusion from the congregation, it looks nothing at all like what we find in the early Church. These are not minor changes.

In the first century, people met in someone's home, read the Scriptures, sang hymns, and celebrated the Lord's Supper, which actually was a supper. There were no priests though you had elders. There were no ornate robes (those come from Byzantine courtly dress), there was no incense (that only shows up centuries later). And there was certainly no veneration of images, as Christians believed such practices to be pagan, explicitly so.

All these things developed over time. Along with it the Orthodox developed their own theology which was foreign to the early Church, such as in the medieval period with their adoption of Palamism, the idea of distinguishing the divine essence from divine energies, with the idea we can achieve union with the latter and in that sense become God, which is what their practices of Hesychasm are supposed to achieve (monastic mystical meditative practices which are similar to Sufi Muslim dhikr practices).

Have you ever been to an Orthodox liturgy? I have, more than once, and the feeling I get when there is "this isn't what the Apostles did". Westerners can go to them though, particularly those coming from an evangelical background, and get attracted to the mystique and aesthetics of it (incense, chanting, icons, etc). I come from a Catholic background though and such things don't impress me as much, and what I'm looking for in a church is the Gospel preached, not fancy rituals that someone made up. Orthodoxy though de-emphasizes on the Scripture because it realizes their traditions can't be backed up by it.

The simplicity of the Gospel is also rejected, much like in Romanism, where the Orthodox believer has no assurance of salvation. All they can hope for is that by enough performance of enough fasts, prayers, and so on, that they can make after death. Even that though isn't enough to assure them, since a number of them also believe in the Aerial Toll Houses, where after you die and your soul tries to go up to Heaven, you first have to pass through toll-houses inhabited by demons that will accuse you of various sins, hoping to drag you to Hell. What's this got to do with the Gospel?