“Constitution provides for the freedom from religion” is not contradictory to the 1st phrase of the 1st Amendment: “Congress shall make no law respecting an establishment of religion”
Well, not contradictory, perhaps, in that the Constitution only prohibits the establishment of a state religion, and nothing else. However, this also means that the Constitution does not enumerate a right to be free from any manifestation of religion. Further, the existence of any such right is precluded by the undisputed right of all citizens to the free exercise of their religions. The very concept is ludicrous.
Another argument is that nothing can be a right unless it is pleasing to God. Atheism is not pleasing to God. Ergo, there can be no right to freedom from religion.
I just assume that there are other arguments that didn’t occur to me.