http://www.huffingtonpost.com/2014/10/02/antonin-scalia-religion-government_n_5922944.html?ncid=txtlnkusaolp00000592Okay, I can SOMEWHAT understand his reasoning. On the other hand, insisting on reading the Constitution solely according to what (you think) the original writers' intentions were shows nothing but fear and contempt for the fact, recognized by the fact that we have an amendment process, that society changes and evolves. If we kept solely to the "original text", not even the Bill of Rights would be included. Black people would still be legally only worth three-fifths as much as a white people, women would still be seen as nothing but breeding chattle and Native Americans would be left out of consideration altogether. To say the Constitution can only be properly read an interpreted through how you think the original writers intended is to raise them to the level of gods, omniscient and infallible.
Additionally, to say that the government must be neutral between different religions, but can still favor religion over non-religion, is to set a very dangerous precedent. By that logic, all one religious group would need to do in order to strip a rival religious group of their rights is to engage in a publicity campaign to convince a large enough swath of people that the rival wasn't "really" a religion, made all the easier by the fact that "religion" is never defined in the constitution, and you would be very hard-pressed to find two different people who would agree on a definition in all the particulars. We see this in the Islamophobia of the Republican Party, with Paul Ryan claiming that First Amendment protections don't apply to Muslims. From there, it's a very short step to theocracy. The only way to remain neutral in religious matters is to remain neutral in ALL religious matters, including between religion and non-religion.