Religion and conservatism are not inseparable. Nor is socialism and secularism.
Christians do not have to be fascist (as you seem to be alluding to by mentioning book burning) or totalitarian. To say that is so is to say that Christianity is inherently fundamentalist in nature, despite the obvious contradictions between far-right theocrats and the book.
On the other hand I agree it is good to ask why religious people may feel it is a sin to think differently. Yet this usually stems from an attempt to gain power?not converts per se.
Religion can be used for many things, from sedating the masses to creating an open and thoughtful environment, from waging war to making peace. Yet to say that religion is one and only one of these is to make an absolute claim?exactly what secularists despise about fundamentalism.
One does not need to be an atheist to “embrace the truths, rights and values” that come along with being human. Thank God.