Ronald L Giese has written an excellent lengthy piece in Themelios addressing the theology of the “online church”. Here is his conclusion:
Online church is not church. This is a contradiction, not an oxymoron. Some of the things a church does can certainly be taken online. Perhaps some parts can be done better online, in certain contexts, than in person. Perhaps others are best done in a hybrid model. The reason that online church is not church is at least two-fold.First, all the indicators, both historical (the past and future temples), and in imagery (the ramifications of the church as temple now), are that God’s dwelling in the church is in a place. And the indicators are that this place is in one place, the local church. So yes, this third level of God’s presence could exist in thousands of places at one given time, since there are thousands of (physical) churches that meet in a given time zone on a given Sunday. But the third level of God’s presence does not occur in one “church” that is really 800 physical locations. That is rather the second level of God’s presence, his indwelling of each believer. Similarly, even though the digital world has been redefining terms for decades—such as a digital “presence” or “place”—we can’t just throw a term into a new context and assume that the New Testament allows for that in its theology.The second reason that online church is not church is that it minimizes biblical anthropology. It is not only assumed, but often stated, that online church can do discipleship, fellowship, the “one another’s,” even the sacraments, just as well as physical church. But the Bible nowhere teaches that we can commune, fully, with God in our “soul” only, without our body. In fact, the Bible teaches the opposite, that physical bodies are an integral part of God’s sanctification and redemption.
The quote above refers to the different levels of God’s presence in creation. The first level is that God is present everywhere. He is “omnipresent.” So even where there are no human beings, God’s presence is there (Psalm 139:7–12).
The second level is God taking up dwelling in a believer, by His Holy Spirit, once the person is a new creation, born again (1 Corinthians 6:19; John 14:16–18). The third Level which he talks about is God taking up dwelling among His people, the local church, when they gather (1 Corinthians 3:16; 2 Corinthians 6:16; and Ephesians 2:21–22).
The point Giese is making is that God is present in the life of a believer in a different way than God is present, say, with the stars. And it also means that God is present in a physical gathering of of a local church in a different way, different than God being just present as each single person worships in the group. This inevitably means that God’s presence is not in the “online church”. It is not church.