From what I have read, there is no successful a priori argument for God. You can't merely define him into existence. Philosophy alone can't get you there.
So you have to offer some variety of evidence supporting God's existence. If naturalistic explanations of the available evidence are more persuasive, then there are fewer and smaller gaps in our knowledge to plug any God into. Beyond a point, there is no longer enough room for an all-powerful, all-knowing, perfectly-good God to operate.
In other words, he should be much more obvious if he existed.
So you have to offer some variety of evidence supporting God's existence. If naturalistic explanations of the available evidence are more persuasive, then there are fewer and smaller gaps in our knowledge to plug any God into. Beyond a point, there is no longer enough room for an all-powerful, all-knowing, perfectly-good God to operate.
In other words, he should be much more obvious if he existed.
