Lyrics:

I was*
I am
I am to come
I was I am
I am to come I was
I am
[etc]

*[note: The words are: 'I am to come' and 'I was to come'
She begins to blend the two together as she gets in to it (the song), and some times, it it more like: 'I was, I am, I was, I was, I am to come.'
It is the inversion of 'Who was, is, is to come' of the Revelation, attributed to the Good.
Here, the 'Bad', (the Beast, 666) turns this phrase into Ego, (first person),
and tries to be born again, or to give birth to another Ego, or to 'make love' to is own self and so on.
Vicious circle.]