When a couple who had converted to Orthodoxy described their journey, they told us about visiting various evangelical churches. Their reaction: "It's nice, but it's not church."
Think about the services in many evangelical churches. If you didn't know the language, what would there be to distinguish the service from a concert/lecture? Sure, some people may raise their hands, but you see plenty of hand-waving at some secular concerts. Yes, someone might bow their heads to pray, but interestingly, the Bible never mentions anyone bowing their heads to pray. Jesus lifted His eyes to the heavens.
Walk into a typical evangelical church, and it might look like a hotel, a school, office or even a warehouse, but not like a church. There may be a cross somewhere, but there is nothing that sets the building apart as a place of worship.
This is often intentional, part of the "seeker friendly" model. But what are seekers seeking? If they are seeking something "not of this world," do we want it to look just like the places they hang out in all week? If they are looking for an encounter with the supernatural, will they find it in a lecture or a concert? Some food for thought.