These are some of the faulty reasoning skills I've observed theists use in a discussion....

"Belief is a choice"
You'd usually see a comment like "I choose to believe..." when actually beliefs aren't choices inwhich one could suddenly play out as though a deck of cards,but beliefs are held when a person is convinced that a statement or explanation is true or likely true(or even plausible)...
People don't pick beliefs, they are convinced by them...

"My belief is true because it would be bad if it wasn't"
This is basically an argument from consequence,it has no basis in facts,nor the reality of the situation but poses a barrier to keep believers in the belief...
Therefore to a believer it would be bad if there was no "life after death","heaven","reuniting with loved ones",etc because they don't want to ever consider a reality that is anything but oblivious to their existence..
So typically a theist may lay in comfort by having thoughts about the ideas that they believe have to exist(and as usual it would be bad if it didn't)
Many things would be bad if it wasn't true, that doesn't suddenly make it true,it would be bad if I had another accident tomorrow-does that mean I shouldn't go out because it would be bad if one thing were true?

"If you can't tell me every single detail, then I can believe anything"

To a theist,if anyone should offer an account that is based on the best evidence obtained up to that moment,it has to be either extremely simplistic or extremely detailed...
A theist lives in a mental constraint where things must either be 100% white or black,and yet theists still give apologetics towards doctrine that are by definition self contradictory(perfect justice and mercy co-existing when they are mutually exclusive)...
Can't tell every detail of 9-11? Well it was a cover-up..
Can't tell every detail of where hiv came from? well it was "god's plan for homosexuals"
Can't tell every detail on evolution? Then it's wrong..
Can't tell every detail on existence? "god did it"


"The evidence of god is in/or written in the bible/scripture"

To be perfectly clear,the bible is the claim-not the evidence....as much as theists may want you to believe the bible is "the proof",it is nothing but the pool of accounts from anonymous authors and hear-say accounts that have been re-interpreted over and over again till it is so vague anything can be said about the passages(this is why theists don't share the same ideas on doctrine)
And then again the process of reviving a dead language is somewhat futile because no context can be accurately played out as whether it should be figurative or literal..

"Disproving secular ideals/concepts somehow affects atheism"

This is usually when a theist thinks that disproving a theory that best accounts for a phenomenon would affect atheists...
It would have been great and even enlightening if they could disprove any theories(because it would broaden our knowledge),but all they can come up with is...
If the earth is 4.5 billion years,why is it still functioning-according to the theory of thermodynamics it should have exhausted all energy to do work(ignoring energy gained from the sun and the earths core)....

This leads us to the next faulty reasoning...

"By merging my understanding of scripture and modern knowledge,we can know everything about god's word"

This gives rise to fundamentalism and extremism...

If public schools don't teach a literal six day creation,all hell breaks loose.
If someone labels a drawing "Muhammed", all hell breaks loose.
If creationism isn't being endorsed,all hell breaks loose...

Sadly some people of faith go berserk when a modern interpretation of scripture is ridiculed or ignored,leading to various forms of violence and misinformation.

"I can't explain what happened but I believe it was supernatural"
This is an age old dogma of when humans knew very little of the world,the unexplainable were regarded as sacred secrets of existence.
It is basically using a bigger mystery to cover a smaller one...
Don't know where rain comes from? well a magic invisible tap is above the sky and there's also a guy there that turns it on when he's bored.
You'd notice that the above example is making a lot of deliberately untestable assumptions about where rain comes from...no mention is made of how one could know or even grasp this...