It's better to make them assess what they actually believe any why, point out any fallacious arguments and the generalised reasoning they use - show them that such reasoning could be used to justify any supernatural phenomenon imaginable and then in the end hope that they realise that their theology is no more valid and has no more objective verification than anyone else's theology.
At best you could convince them that there is insufficient evidence for organizing their lives around an unprovable idea, mid ground would be to convince them that while Deism is still potentially true but unproven non the less that their theistic beliefs are completely wrong and believing any man made religious doctrines is far removed from rational thought, but more often than not they have too much invested in such a theology to critically analyse it, they have friends, family, colleagues, congregations ect that would potentially be demolished if they declared that their theology is unreasonable to believe. The emotional/relational cost of disbelief is far too great for some people to consider.
A lot of the time you will find that Theists will completely dodge questions (Yes i'm talking about you, frodo) or when their conclusion from reading of the bible is disagreed upon by either Atheists or those from other denominations they will claim things like "you need more background info to understand it" or "you didn't correctly assess which are metaphor and which are literal" or "you didn't want to believe it enough" - all of which are complete cop-outs that wreak of special pleading (Once again, take frodo for example).
At best you could convince them that there is insufficient evidence for organizing their lives around an unprovable idea, mid ground would be to convince them that while Deism is still potentially true but unproven non the less that their theistic beliefs are completely wrong and believing any man made religious doctrines is far removed from rational thought, but more often than not they have too much invested in such a theology to critically analyse it, they have friends, family, colleagues, congregations ect that would potentially be demolished if they declared that their theology is unreasonable to believe. The emotional/relational cost of disbelief is far too great for some people to consider.
A lot of the time you will find that Theists will completely dodge questions (Yes i'm talking about you, frodo) or when their conclusion from reading of the bible is disagreed upon by either Atheists or those from other denominations they will claim things like "you need more background info to understand it" or "you didn't correctly assess which are metaphor and which are literal" or "you didn't want to believe it enough" - all of which are complete cop-outs that wreak of special pleading (Once again, take frodo for example).
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