When you say something must intervene between the universe ( including men ) and God, you are assuming there is a barrier or wall that exists.
But, as I have shown, that is not true. There is no barrier and there is no need for some connecting " boundary " ( which is a very poor choice of metaphore). For example, the Bible is a complete history of interaction between God, the world, and man. And we have instances of the same thing taking place right up to our own time, appearances of the Blessed Mother. visions given to the saints, and of course the best example is at the consecration of the Mass when the priest makes Christ present in the Eucharist.
And aside from all that we have evidences left by God in the very nature of things. This is what I call natural " revelation, " all of nature tells us God exists, and that is a Divine communication…
If you are going to exclude God from interaction with the universe, then you are left with a universe which is unexplainable. And as St. Thomas said and the Church testifies, that is not possible, It is not possible that the universe accounts for its own existence. And Thomas Aquinas has demonstrated why such a thought is not rational. And thousands have followed him and offered their own explanations why this is irrational.
Linus2nd