The ground floor of the church building is the life of the Spirit, that is, being led by Him.
There is no other life, no other functional place of ministry than to be spiritually minded, and any ministry that occurs outside of that will only reproduce after its own kind. Any other form of church is a hollow, man-made shell, with no lasting fruit nor legacy.
Jesus came and demonstrated the first spirit-led life. He was cut off from this Earth through the waters of baptism, lived apart and separated in the Spirit realm of the Holy Ghost, and only after His death was he granted brothers.