This article from The Atlantic last year looks at the shift in ways that Jesus has been popularly depicted in film since 1970. It considers the film version of Godspell rather than the stage production, but gives some insight into the context in terms of religious movements and the media landscape, then and now.
“Hippies and their religious analogue, the Jesus People, defined themselves by experimentation. … For the latter, it meant relating to Jesus in new ways. Their ‘buddy’ Jesus ‘took a bad rap.’ The new vernacular even had a new Bible, The Way, which translated biblical texts into what seemed then a ‘cool’ idiom.”
“Both [Godspell and Jesus Christ Superstar] portray [Jesus] as a hippie opposed to the hypocrisy of the religious establishment, but they draw on conflicting impulses from the sixties in creating those images. As every student of the decades knows, the sixties went in like a lamb and out like a lion. They were peace and love and flower power: Woodstock. Then they were race riots and overdoses and Vietnam: Altamont. Superstar grows out of the sixties’ dark side. […] Godspell, by contrast, is a product of the sixties’ bright side. True, its Jesus flays lawyers and Pharisees as snakes and vipers, but […] he sings about love and harmony, thanks God for sunshine and rain, and rejoices in a community of caring friends.”
Check out Stephen Prothero’s fascinating and detailed history of Jesus’ place in American culture (American Jesus: How the Son of God Became a National Icon). In addition to his direct discussion of Godspell, the whole of the fourth chapter, “Superstar,” provides excellent historical context for the religious trends behind the concept of a hippie Jesus.
Often compared due to the similarity in subject matter and the time of their first productions, this LA Times piece looks at the differences in these two musicals and why people—religious and secular alike—still love both.