In general, I'm always pretty skeptical of any remake, sequel, prequel, reboot, requel, etc. Especially ones that involve riding the coattails of a great 70s horror film (see the latest Exorcist).
But even I have to admit the trailer for this looks pretty decent. Doesn't mean the movie will be, but so far so good. It probably helps that I never really loved The Omen all that much. It always seemed a lesser film than things like Rosemary's Baby, The Exorcist, and The Shining from that era of horror. I respect it for what it is, but creepy children in horror is a weird genre that does nothing for me and so the fact this story is going to focus on something other than a creepy kid might be good for it.
I should add though, that my bar for religious horror is pretty high this year, as I just saw Immaculate last weekend and it's going to be hard to top that I think. The film did not hold back any punches and was smartly written with a very clear point, a point it conveys without being too heavy handed and leaves the viewer with plenty of room for contemplation. Leaving the theatre I may have said it was a bit too lean, which would be a rare criticism from me because I love lean, concise films. After thinking about it for a week, I think it's efficiency will work in the long run and it's themes and messages will still be interesting many years from now.