Although I'm no longer Christian, I found this a fascinating look at the Pentecostal culture. Even at my most religious, I was in mainline denomination. We didn't do speaking in tongues, snake handling, or drinking poison. My baptism was a dab of water on the forehead. So, it was a look at an alien culture to me, even though I was a Christian for the majority of my life.
The opening scene is taken toward the end of a Pentecostal service. My mainline upbringing leads me to wonder how much of the hand waving and what looks like ecstasy is performance. But, it also illustrates why such churches keep drawing people.
The look at different subcultures of the Pentecostal movement was eye opening. I didn't know that there were still churches that opposed pleasure and happy music. And it was interesting to see some of the individual interviews such as the man with the stick filled with the holy ghost. The look at the honky-tonk far outside of town was also interesting.
I lived for a time on the outskirts of Appalachia when I was a child. I knew this life, but only that it existed. The whole thing was eye opening.
And it's worth pointing out the power of music. You will be humming tunes from this movie later, even if you don't believe in the superstition behind them. Music has a lot of power.