God's triune nature means that God is social or relational - God is the "social Trinity." And for this reason, we can say that God is "community." God is the community of the Father, Son, and Spirit, who enjoy perfect and eternal fellowship.
Churches are supposed to be a reflection of this Trinitarian community. Meeting in a home (instead of a church building) doesn't guarantee that kind of fellowship but it creates a context where it is at least possible.
The early church didn't meet in homes because they were afraid of persecution. They met there because they longed for this kind of community they had tasted with Jesus.
"...that all of them may be one, Father, just as you are in me and I am in you." Jn. 17:21