Atheists, what are the most convincing theist arguments you heard of?

[Whateverist]

...this atheist is more than happy to acknowledge the presence of an ineffable otherness within.  I value its participation and inspiration at all times.  It makes the world a more complex and also satisfying place to conceptualize an otherness within.  Its happiness is key to my own.  It tends to keep alienation at bay and provide a robust answer to existential questions.

During your reflections have you ever felt the presence of Love coming from outside yourself?

The source of the mystery is pretty much a mystery. How could anyone know what was coming from inside and what outside? I assume when you speak of experiencing the numinous you refer to being conscious of something which ordinarily we wouldn't be. How at such times can you be certain that what you are experiencing is the ordinarily transparent apparatus of consciousness or some secret aspect of the world?

 But I would never seek to write over what it has to offer with anything off the rack or which pretends to be authoritative.  Only the mystery itself will do.

I see 'holy books' as treasure trove of insights into how people from distant times and far away places what experienced and tried to make sense of that mystery. Yes, they often include various prohibitions and obligations, but those seem more like culture specific ways to attain and preserve that relationship with the source of that mystery. I realize that literal-minded people, believers and skeptics alike, don't take that approach. I find that very sad.

I see them as suggestive. By looking over a suitably wide variety of such accounts one perhaps gains some insight into the sorts of experience people report. But what to make of it? Only someone who has asked themselves the same question could possibly answer that. However, realizing that they were in no better position to answer than are we means we shouldn't be too quick to adopt their answer. The mystery is the mystery for structural reasons, it isn't possible to cash it in for something objective.