One by one, using the rocks you find along the way, you can build 'most anything. But you must be sure to fit them together. You must give each one other rocks to lean on and support. Rock by rock you can make the sturdiest of fortresses.
I was looking this picture of a wall I took out in Desert Hot Springs. It has stood the test of time. I suspect that is because the rocks work together. An earthquake may shake the wall and send the rocks tumbling but only if the builder did not take care to putting it together.
Now isn't that a bit like the Creator did with mankind? Interesting. As they say, "United we stand..."