If you’re planning your first visit to an Orthodox church, you may have done a lot of reading in preparation. Wondering about what kind of mystical, otherworldly things you might see is common.

Frederica Matthews-Green is a writer and speaker on Orthodoxy in modern society. Her piece on the 12 things she wished she’d known before her first visit to an Orthodox church is great reading, and might help ease some of your concerns.

Orthodox worship is different! Some of these differences are apparent, if perplexing, from the first moment you walk in a church. Others become noticeable only over time. Here is some information that may help you feel more at home in Orthodox worship—twelve things I wish I’d known before my first visit to an Orthodox church.

1. What’s all this commotion?

During the early part of the service the church may seem to be in a hubbub, with people walking up to the front of the church, praying in front of the iconostasis (the standing icons in front of the altar), kissing things and lighting candles, even though the service is already going on. In fact, when you came in the service was already going on, although the sign outside clearly said “Divine Liturgy, 9:30.” You felt embarrassed to apparently be late, but these people are even later, and they’re walking all around inside the church. What’s going on here?

In an Orthodox church there is only one Eucharistic service (Divine Liturgy) per Sunday, and it is preceded by an hour-long service of Matins (or Orthros) and several short preparatory services before that. There is no break between these services—one begins as soon as the previous ends, and posted starting times are just educated guesses. Altogether, the priest will be at the altar on Sunday morning for over three hours, “standing in the flame,” as one Orthodox priest put it.

As a result of this state of continous flow, there is no point at which everyone is sitting quietly in a pew waiting for the entrance hymn to start, glancing at their watches approaching 9:30. Orthodox worshippers arrive at any point from the beginning of Matins through the early part of the Liturgy, a span of well over an hour. No matter when they arrive, something is sure to be already going on, so Orthodox don’t let this hamper them from going through the private prayers appropriate to just entering a church. This is distracting to newcomers, and may even seem disrespectful, but soon you begin to recognize it as an expression of a faith that is not merely formal but very personal. Of course, there is still no good excuse for showing up after 9:30, but punctuality is unfortunately one of the few virtues many Orthodox lack.

You can read the rest on her website.