Why do the religious block atheists, and often make outrageous claims about what we say?

I block no one, I can't speak for the rest.

As you described, “anonymous trolls who pretend to be religious” would likely be the majority of those blocking you.  And by your own definition, are not actually religious people.

I would encourage you to be more discerning to which users you reply.

Because it is glorious

Why are you so obsessed with us? How is it your business? What’s your problem? Just go on with your life and never mind what we’re doing. It’s none of your business. Get over yourself. You’re not important or relevant at all in the scheme of things. You’re here to work the land... that’s it, that’s all. If you cease to be useful you will be obliterated. End of story.

Because they are little snowflake cowards. They know they cannot show their god is real and it makes them angry like two year olds so they stomp their feet, hold their breath, then make outlandish claims about atheists because thats all they have left. They are not interested in having a conversation or even trying to convince us even though their god commands them to. If they can ignore their god, we can too. There is no need to block the losers. 

They seem to lie as a matter of course, as if telling the truth was foreign to them.

Very likely fear - they are afraid that atheists will refute what they claim and they have no proof to support their claims.

And the only responses they get would be from others that think like them, so they believe they have more support for their beliefs than they really do.  Its a form of delusion, which religious nutters are very good at.

The biggest culprit of this is "flourkid".

And it is done merely to rile things up... to stir the pot.

If you are talking about Flowerchild they also block Christians like me.  I suspect he is more interested in causing upset rather than religion