I'm not all that excited by either "secular" or "non-Christian." Neither one of them really captures what we do here.
Many, if not most, of the posters and participants are, in fact, Christians. Many are explaining the beliefs and practices of their own faith. To say that this website is "secular" or "non-Christian" conveys the idea that we are a bunch of non-Christian, non-religious folks talking about Christianity. That would not be an accurate representation of the site. Yes, there are non-Christians, atheists, and agnostics actively participating here. And that is good. But this is certainly not an atheist or agnostic website in overall tone and participation, as would be suggested to many people by applying the words "secular" or "non-Christian" to the website.
I am also not excited about the sometimes used "scholarly" or "academic." The reality is that most of the answers here are not actually written by religious scholars. I happen to be one in my own particular field (Swedenborgian faith and practice, and related Biblical studies). But many others answering questions here are not. And we certainly don't require scholarly or academic credentials for people to post answers here. Only that the answers provide good, solid, well-referenced information that clearly addresses the specific question asked. (Unfortunately, many of the answers fall far short of that ideal.)
"Scholarly" and "academic" are closer to what this website is all about than "secular" or "non-Christian." But they still don't quite capture the essence of the site. Just as this site is not sponsored by and in support of any religious institution, it is also not sponsored by any academic institution. We really are not an "academic site," nor are we really a "scholarly site." Much of the content here would not pass muster at a respected academic institution. And as long as the answers are good, I have no problem with that.
My current thoughts of how to describe the site are therefore along the general lines of "scholarly" and "academic," but with fewer connotations of academia. I would suggest as possibilities:
I like the first two better than the third. And of course, any of them would have to be embedded in explanatory text about the nature of the site.
I would also suggest that in our masthead, instead of having "Christianity" by itself, we add, in smaller letters, perhaps above and offset from the main title, the word "about," so that it reads something like this:
This would be a tip-off to the actual nature of the site: that here we answer questions about Christianity, rather than advocating Christianity. I expect that a reasonably skilled graphic artist could make it look good and artistic.