I've defended unblack metal (Christian black metal) in the past. Most unblack metal is actually some of the most Biblically-based, uncompromisingly Christ-centered music I've ever heard -- much more so than those generic and borderline gross "I love the way You love" lyrics in a lot of popular "Christian" music! From the Bible passages in Elgibbor's lyrics, to the spiritually encouraging lyrics of Dying Blaze's "Сокрушая тьму".
But at the same time, there are still some ways I feel like parts of the scene could improve. We're definitely taking steps in the right direction, for sure, now that that awkward phase in the early 2000s is over where it seemed a few people couldn't tell if they were really into Christianity or not, and there's a solid scene going now. But there are still ways to improve, and a particular few have really stuck out at me lately.
First, it is possible to be too direct, but sometimes, the problem is that some bands aren't direct enough. I often edit Christian bands' pages on Metal Archives (doesn't seem like there are very many fans of Christian metal on that site) and I added a black/folk metal band last night. They have ties to a Christian church in Bolivia, one guy wears a cross necklace, etc. But the problem is, they aren't very obvious about their message. Without knowing the band at all, a moderator actually changed their genre to "pagan black metal" based solely on their sound. Not that black/folk metal is bad; the problem is, I don't have objective enough evidence that they're not pagans, since there's no other sign of their beliefs (such as lyrics, or something), so I guess that's what their page is going to say for now.
And another band released an album awhile back called "Under a Black Sky of Blasphemy", and they have an inverted cross in their logo. If it weren't for a few subtle clues, I wouldn't even know that this was a Christian band in the first place, and that's a problem. If you know the unblack scene at all, this is a pretty good example of another problem I see: bands that simply try to be "darker" or "more extreme" than the secular scene. Now, this is one that I'm kind of guilty of myself with that "War EP" I did back in January, though that was actually unintentional. I actually didn't want it to be quite that dark; I just did, pretty much, a one-take improvisation of some ideas, and, well, that happened! But I think most people reading this know what I'm talking about; the bands that take it too far with the medieval war metaphors, bands that take the "dark" themes too far, etc.
I really don't like giving examples; I don't want to disrespect anyone in the scene, but look at this:
You cannot stand against them
The hounds of Heaven seek your soul
No one and nothing at all can escape this force
They do not break their ranks
Who can endure it?
There is no refuge from them and you cannot stand against them
See, even now they come your way
The hounds of Heaven seek your soul
These kinds of lyrics aren't really doing anything to glorify God. They're definitely more "vicious" than what certain secular bands are doing, but the aim with Christian music isn't just to outdo each respective secular scene (though I certainly encourage doing it musically!), it's to spread a Christian message. Let's just remember to keep God first in this music. The violent/dark themes of extreme metal can be an interesting canvas for ideas (think of Christian goregrind), but it shouldn't be our primary focus. It should be about glorifying God through these themes and reaching out to those who are lost in them. (Edit September 2016: I used to have other lyrics here too. I've since read some information about those lyrics and they do make a lot of sense now, so I removed them from this part of the post.)
The last problem I've noticed is one I've mentioned elsewhere before: the hexagram. The "star of David". Several bands use this symbol in band logos or album art. There's very little, if any, evidence that it was ever associated with David or with Jews, before recent times, but there's ample evidence of its association with witchcraft. I can't complain too much about it, I guess. The meanings of symbols can change over time. There are some who are trying to take back the inverted cross symbol, and have it represent Peter's crucifixion again. But we should still be a little cautious with using these symbols everywhere. Especially since the hexagram isn't associated with Christianity at all, and is associated with two non-Christian faiths, witchcraft and judaism.
These are some things I think we should keep in mind in the future. I'm half exhausted right now while I'm writing this, but I wanted to write it. And I'm not claiming at all to be some kind of messenger being sent into the unblack scene, it's just observations I've made since I'm such a big fan of this music. Unblack metal is still my favorite genre, I just think some of these things should be taken into consideration in the future.
Edit: With all glory to God, I just remembered one more thing I wanted to add to this post. It's an important point, and I urge you to read it here.
God bless you all, and guide you all according to His perfect will. In Jesus' name. Amen.