Jesus said, "I will build My Ekklesia", and so we know that this Ekklesia is not built by man, it's not organized by man. Man is not the author or the creator of it. Jesus is building His Ekklesia, and so, it is a thing that is quite beyond man, quite beyond what man is capable of. It is not a system of man, it is not an organization of man, it is not a denomination of man, it is not a movement of man. But just like the new Birth, the Ekklesia is "from above", something that originates in the Spirit and by the Spirit. And so it is spiritual.