Hmm... Very interesting.
I'm not gonna touch base on the religious aspect just to keep things simple. As for the lyrics, it's up to you really. Make two copies, one with the whisper and the other with normal singing and compare for yourself. Remember, you're audio reflects your opinion so if you think it needs to be whispered, then whisper the lyrics! In my opinion, I think normal singing would work better however. But the simple lyrics really work with the simple melody
Now to the music itself! Sounds solid really - nice work! The only thing I would suggest is to add some more melody next time. The instruments remain simple and true to the song. The whole thing sounds very cleansing. Awesome job!