As best as I can surmise, the first stanza is about social injustice, racism in particular, something their middle class listeners may have heard of but haven't directly experienced to any great extent, much less done much about. The chorus is about the fading of social harmony to be replaced with hostility. The "it" we can't escape is revolutionary sentiment leading into the next verse about the poor and disenfranchised rising to overthrow the rich and powerful, and a once prosperous and peaceful society dissolves into bloodshed and chaos or tyranny. "Heaven" has turned to "hell", and the illusion of freedom has been broken.
As best as I can surmise, the first stanza is about social injustice, racism in particular, something their middle class listeners may have heard of but haven't directly experienced to any great extent, much less done much about. The chorus is about the fading of social harmony to be replaced with hostility. The "it" we can't escape is revolutionary sentiment leading into the next verse about the poor and disenfranchised rising to overthrow the rich and powerful, and a once prosperous and peaceful society dissolves into bloodshed and chaos or tyranny. "Heaven" has turned to "hell", and the illusion of freedom has been broken.