Who can show me in the US Constitution where one can find “freedom from religion”.

You won’t be able to. It’s also not found in Jefferson’s famous letter to the Danbury Baptist Association. 

The reason you won’t find it is because 100% of humanity is religious. 

You see- whether someone espouses Christianity, Buddhism, Islam, Judaism, Shintoism, Animism, or any other named religious system, or claim to be an Atheist or simply  “non-religious”, you are still practicing a religion. 

Yes, Atheism is a religion. You just elevate yourself as your own personal god in the place of the Creator.  The god of Atheists – is themselves, but make no mistake – it is still a religion.  This religion even has a name – Secular Humanism, a subject that is taught in schools.

Religion is best defined as a system of beliefs that direct or influence your life. Those who claim to be Atheists, simply (think they) direct their own lives by their own personal values and desires. But self-worship is still a religion. 

1st Amendment:

“Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof…”

Of course, when one actually studies the context of the writing of said Amendment, reads Jefferson’s above-mentioned letter as well much of the remaining bulk of the writings and statements of the authors of the Constitution, we find that there was an expectation of some kind of religious affection, not only in our government but that a moral society, based on the values espoused by the “Christian religion” was the foundation the unique document was built on.

Where all the “founding fathers” Christain?  Not even if you. were to stretch the label even beyond modern over-use. But almost all recognized a God (many were indeed Deists), and almost all were educated in what would be considered bible schools or seminaries today.

The first government-funded school textbooks in the Americas?  They used Bible texts for reading and study. Every session of the US Congress began for well over a century with a Christian sermon delivered by a Christian preacher and included Christian prayer. All of this raised no opposition, even from the Deists among the delegates.

The real “wall of separation” that Thomas Jefferson eluded to in his letter was one that was to prevent the totalitarian single church-states that the early settlers had often fled from. It was not viewed, when the Constitution was penned, as freedom FROM religion, but explicitly was to prevent a single, national religion (such as Catholicism, Lutheranism, Anglican, etc.), and the often oppressive Theocracies those represented. And it is in the full set of letters exchanged between Jefferson and those Danbury Baptists that actually help us to understand this. You see, the Baptists in Connecticut were being oppressed and shut out of having any voice in the state government. The government of Connecticut was completely dominated by Congregationalists. Even Jefferson, as President, didn’t seek to remove Christianity (much less all religions) from the public square, or even from the influence of Christianity ON the government.

Indeed, the removal and avoidance of all religious connections and influence on our government is a relatively recent movement, that is more often than not, exercised almost exclusively on Christianity. In fact, there is a growth in teaching many world religions and even training public school students to memorize and recite Islamic prayers and to practice other religious rituals as a form of teaching “diversity”.