Two sons of David; two temples. One of stone; one of living stones, of people.
Why is it wrong to say that the Church is invisible? For the same reason it is wrong to say it is visible!
We can only see part of it. The part where we are. The other living stones to whom our lives are connected. We can partially glimpse down the structure to see where the Lord has joined other living stones and we can see that vast foundation of the Apostles and Prophets with Our Lord being the cornerstone. We can't glimpse up and out and all around. Not yet. [And it is rather silly to imagine that the wall as I know it is the whole of the building! No, the building will finally consist of all those in whom the Holy Spirit has wrought the saving faith that connected them to the Lord Jesus and who persevered in that gift by God's grace to the end.] But for the duration of this age, our vision is always rather limited.
That's okay. When comes the Last Day, we shall see the New Jerusalem for the first time in her wholeness and fullness - with such glory as never dared to dream or imagine! Until then, THE Son of David is busy at work building His temple, a house for the name of the Lord, the God of Israel. Just to be a living stone and part of it - that is glory beyond words.
"The Lord has sanctified us in the true faith! O come, let us worship Him!"