Lyric discussion by cubfever7 

Cover art for Crystal Blue Persuasion lyrics by Tommy James And The Shondells

The song is about Tommy's conversion to Christianity. You can go to the last book of the Bible and in the first couple verses see part of his inspiration. But Shekhinah light or glory is where he got the purse blue light idea. This song has a wiki page that explains it--and there's an interview on YouTube with CSN that Tommy did that gives good insight as well.

When you think about it, the spirituality of the song is pretty overt: "Maybe tomorrow When HE looks down On every green field And every town All of His children And every nation They'll be peace and good brotherhood"