I am going to debate a theist over the existence of god soon. What are the best arguments you ever heard from theists? Any tips on what topic to avoid in such an discussion? 
Thanks in advance

I have yet to see one of them produce an argument that can survive the "do you have evidence for your claim" test.

And it comes as a real shock to them when you tell them that their silly-assed bible is not evidence.  It is merely the claim.

My experience is that they will make grand claims at the beginning that they can't back up, will devolve into circular arguments, fallacies, and the like in the middle, and will eventually come down to "who are YOU to question god?" and threats of hell.

There aren't any.

(April 8, 2018 at 5:29 pm)ShirkahnW Wrote: I am going to debate a theist over the existence of god soon. What are the best arguments you ever heard from theists? Any tips on what topic to avoid in such an discussion? 
Thanks in advance

Any tips? Yes, read these threads.

Don't get caught trying to disprove god. The ID people love that one.

(April 8, 2018 at 8:54 pm)mh.brewer Wrote: Don't get caught trying to disprove god. The ID people love that one.

It's surprisingly easy for me, but that's just me.

They can't even define it, most of the time. If they do, and it's coherent, it's almost always unfalsifiable. If that's the case, there can't be any evidence for it, so it's just an unnecessary assumption. Job done.

To be honest, the entire definition argument is just semantics wearing a dictionary cloak.

By all standards, we know what someone means when they refer to a god.

(April 8, 2018 at 10:47 pm)Lutrinae Wrote: To be honest, the entire definition argument is just semantics wearing a dictionary cloak.

By all standards, we know what someone means when they refer to a god.

Are you referring to my post?

If someone can't even define the terms they use, then they are talking crap and are wasting everyone's time. That's what pinning the theist down is supposed to avoid. It's not so much an argument as a starting point for any sensible discussion. If the theist falls at the starting line and not even the first hurdle, then that's too bad.