Church has taken many forms over the centuries. But always, Christ's true Church has been some form of the model set down for us in the time of the New Testament by the Apostles.
In order to understand what happens in Christ's Church, however, we have to put both Old and New Testaments together to form the complete picture: it's the growth of the spiritual Son being prepared to live with his Father in Heaven.
" And God placed all things under his feet and appointed him to be head over everything for the Church, which is his Body, the fullness of him who fills everything in every way. (Ephesians 1:22-23)"