This show is a serious case of Mood Whiplash
. It's an interesting, original tale of a goddess who comes to life and tries to revive interest in religion, and often tries to make a serious point about the state of piety in modern Japan and ordinary people's attitude towards Shintou. ... But Nagi goes about her life in a very anime romcomy way, shacking up with the local shrinekeeper and cultivating a big fan following on campus. We meet a kind nun who performs confessions on the street... who is also a member of Jin's Unwanted Harem
and a Bitch In Sheeps Clothing
. In other words, it somehow tries to be both a drama about declining religious belief in modern Japan and the new forms of "idol worship" and another harem comedy. It may seem for a while that the comedic aspect of the series is more important (it usually is in these types of shows)... but the last few episodes suddenly get all serious again as we explore a ghost story and drama brews over Nagi's true identity.
In the end, I couldn't really get into it because the tension between the serious and comedic aspects is too great and the story is usually unclear anyways, but the writing (for the comedy!) is generally pretty funny and the art and animation are also well-done. Jin is definitely one of the more sympathetic harem protagonists and most of the cast is a hoot to watch. For harem enthusiasts, this show is fun if you can get over the religious backstory. For everyone else, the commentary on Shintou, easily one of Japan's most distinctive attributes, might be of interest. But it's hardly a major anime and I wouldn't predict this to become a classic.
P.S.: Actually, the one classic, outstanding aspect of the series is the ending theme. Listen to it. It's one of my favorites from any anime!