You're using the term 'theist' far too loosely.
Of course you should read the whole bible, and in as many versions as possible, as well as study the many different Canons and the history of the evolution of the many stories that have been incorporated into the various Canons.
But don't worry.
Once you have done that and can debate based on what the stories actually say, once you do know the history, the evolution of Christianity, they will still just tune you out.
Anyone so limited that they can only spell a word one way is severely handicapped!
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