In an interview with E! news, Gaga stated that the name of the title was interchangeable. She had used both phrases in the song and they were both very good, so she decided to use both. She continued by saying that the song was about when she moved to downtown New York when she was 19. The lyrics are about how when Gaga moved downtown, she was introduced to an entirely new way of thinking that was so different from the way she was taught. Up till then, iconic imagery had taught her her entire life to look at Jesus and religion a certain way. So she sees Black Jesus as an entirely new way of thinking, which she believed was caused by meeting new people and seeing new things. She says that the Amen Fashion part of the song is about having a new way of seeing is as easy as changing your fashion.
When she sold her sold her soul for fame + money etc. The Illuminati brainwashed her to view Jesus Christ differently, to go toward Lucifer.

"There's no way I could be stopped,
Was taking my best shot,
I had a better plan."

She working her ass off to be famous and for people too listen to her music.

"There's no way I could be stopped,
Was coming for your spot,
I met better men"

I think when she says i met better men, I think she didnt care when she sold it.

"Dancing in my relevation,
Underground pop civilization.
Concrete poetry to feed my mind,
Old symbolism was left behind."

When she says 'old symbolism was left behind' she means that the hand signals, covering her left eye, etc. Was never really done so much in music videos and performances because it would of been too obvious too people who knows what the signals mean. I guess now they dont care who knows/or who doesnt know. They might past it as a conspiracy.

Black Jesus. She doesnt mean "black" as Jesus is a different race. She might mean the opposite of Jesus , which is the devil. She's always using religion too symblozie someone/something else.