Imagine you live in a world where the majority worship's Chutulu. There are a minority who don't worship Chutulu, and nobody likes them. But because there's religious freedoms in place, they can't just silence them or get rid of them from public spaces.
So the Chutulu worshippers hatch a scheme: "Freedom from religion."
Make it so NOBODY can worship in public spaces. Shame the heck out of them, ban it from the workplace, military service, and government.
The idea is that the majority won't be affected much, because they're the majority. But those annoying minority religions, they can shut them up and keep their crap from spreading.
And as a bonus, they can rile up their base against unfairly being prohibited from expression. This makes them from apathetic Chutulu worshippers into angry zealots, which is a good thing for the Chutulu religion.
That's my theory on "Freedom from religion" in a nutshell. It's not an attack on Christianity at all. It's a right to discriminate against non Christians.
A very sneaky way to oppress the voice of opposition religions.