Christ is Head of all individual, 'local assemblies', collectively, therefore, spiritually, of the Universal Church or 'Assembly'. What qualifies any to receive Christ as Head, is to be one individual person, to be "called out" - out of the world, in the world, but not of the world. That makes the Headmastership of Christ totally individual, and impossibly of any locally assembled society collectively. There are not as many 'Heads' as there are 'assemblies'. Christ is One and God is One, and his Church is one, therefore, invisible in its visibility. I have always maintianed, not outside its visibility, and always, inside it; yet invisibly, inside it.
Here to me is the ultimate and final 'definition' of the Church of Jesus Christ: "The Body of Christ's Own" 'sohma tou Xristou', of which "He is the Head" -- "The Head of the Body the Church, the Firstborn from the dead" -- from all the dead whom Christ spiritually ever resurrected, The Head from which "all the Body by joints and bands having nourishment ministered, and knit together, increases with the increase of God" to eventually and at last include each and every one "Called Out".
Here to me is the ultimate and final 'definition' of the Church of Jesus Christ: "The Body of Christ's Own" 'sohma tou Xristou', of which "He is the Head" -- "The Head of the Body the Church, the Firstborn from the dead" -- from all the dead whom Christ spiritually ever resurrected, The Head from which "all the Body by joints and bands having nourishment ministered, and knit together, increases with the increase of God" to eventually and at last include each and every one "Called Out".