Edward Cullen says...

By reading the sodding bible.

This Works!

Firstly... You can't reason with them because their delusion is their source of comfort - their opium.

All you can say is 'I don't believe' and walk away.

I don't even try. It is like having a battle of wits with an unarmed person.

I don't because if they were looking for logic and truth they would have turned away from religion a long time ago. Believers will always believe.

"I don't discuss fiction as if it was real"
.
The purported word of a god would be clear and easily understood by all.
Once different interpretations arise, the premise is shattered and with it the possibility of that god.

You can't change their minds. They think your the antichrist.

THINK

Any claim made without evidence can be discarded without evidence.

Pointing out the unbelievable number of things the bible cites, that have been plagiarized from other ancient texts that came long before it.
Pointing out the contradictions it contains.
Pointing out that men wrote it and god doesn't exist.
Admittedly, I really don't debate with theists as much as I used to. I stay off Facebook, except to engage with family and close friends, who all live elsewhere, and not in any
kind of religious context.
I generally don't go to sites that are populated with believers. Unless I'm feeling particularly feisty and spoiling for a fight. In which case, I will indulge myself.
That happens with much less frequency these days.

I usually use the same book to debunk their ideas. Other times I ask them for any other documentation to corroborate

A simple " fuck off " seems to do the trick ?