Which religions is this song inspired by and what do the metaphors/symbols mean?

I was going to ask this in music.stackexchange, but decided to ask here, as I think the subject is inspired Judaism and Christianity. If there's a more appropriate site, please let me know and I can ask there. The question is related to this one - https://musicfans.stackexchange.com/questions/12481/what-is-the-word-used-in-this-line-of-this-song-for-which-ive-typed-up-these-ly . Would the lyrics in the linked song above be inspired by any particular religion and what do the metaphors mean? I think it is either or both of Judaism and Christianity, and maybe Islam, but I am not sure. The author is Mary S. Applegate, whom I assume to be the same Applegate as the author of "The Power of Love ". On Applegate's Wikipedia page's Associated acts section, I don't find any religion-based artists, if it is the same writer. In particular, what could the name of the artist mean? Who or what is Gabriel? What is the perfect circle of infinity that Gabriel shows? What is the sacred kingdom? What are the forbidden skies? I showed this to a Jewish friend, who mentioned that sin is disturbance of harmony. I'm curious to know more.