Mountaintop: a place where we can cry out our praise to the Lord. This is what God desperately desires for us. Why is that? Each and every one of us was created for it. And the Mass, of course, is the reflection here: of this heavenly liturgy, this divine worship. So we can bring our feeble selves into this heavenly court and worship the Lamb.
We cannot have a proper community, a proper order of the world unless there’s also a union with the right praise and right behavior. That’s why Moses and the Lord God spoke about this on this mountain: praise and behavior guided by God fulfill us with his harmony not only to ourselves but to the whole Universe.