First and foremost before I proceed, let me say that I believe each wing has a gift and charism that is good, and someday the great prayer of us all should be that we are one. The scandal of separation in the body of Christ is something the enemy loves, and in order to build the Kingdom, we must find a way to come back together, however long that takes. This should be the fervent hope of any Christian.
Stories give us hope. But no story, song, or poem can truly satisfy the longing in our hearts. They all seem to fall short. It is like watching a sunset. Though you appreciate the beauty of it all, it fades, and is gone. It becomes a memory, but that memory is not enough to save one from the darkness that ensues. There must be a memory of something that is so powerful that it lives within you as a vital presence—a life that will never die but will well up in one’s heart to the brim and give light and hope no matter what comes. What Tolkien spoke to Lewis about on the Addison Walk was one of the deepest conversations friends could have. It was Evangelium (the proclamation of the Gospel). The great story of salvation is what unites all the wings of Christendom.
The most essential connection, however, is the intimate relationship each of us has with Jesus Christ. When He walked the paths of this world, He knew above all that close personal connection with Him was the way many would come to see the Kingdom, and find their way to follow Him. He did not choose to found a political Kingdom but instead a fellowship of creative endeavor bound to incarnate the Spirit on earth through the great variety of charisms we humans have. 