Deirdre McCloskey in her book Bourgeois Equality - How Ideas, Not Capital or Institutions, Enriched the World (2016), Chapter 41 “Printing and Reading and Fragmentation Sustained the Dignity of Commoners”, explains that the Lutheran and Calvinist Protestant Reformations, which embodied a requirement for more equality and more individualism in the judeo-christian tradition had many precedents.
The first use of a slightly free press was religious. Among the first profitable texts to come from Gutenberg’s press, ironically, were fill-in-the-blank forms for the very indulgences (that is, time off in Purgatory) whose prolific selling in the 1510s to finance the beginnings of Julius II’s Basilica of St. Peter’s in Rome, and Michelangelo’s painting in the Sistine Chapel (irony upon irony), outraged Martin Luther, the success of whose Reformation depended on… the printing press.3
The Church of Faith had earlier and repeatedly challenged the Church of Power— for example, the Henricians from the 1110s, the Cathars from the 1140s, the Waldensians from the 1170s, the Lollards from the 1380s—but failed in a Europe without printing and its widening of literacy.
The economic historian Jared Rubin has shown a powerful effect on the Reformation of closeness to printing presses.4
It was, according to her, the printing press which made possible/successful the Protestant Reformation (understand: not the powerful Renaissance humanist European movement).
So, although the Lutherian and Calvinist Protestant Reformations do show strong influence of humanism (Luther and Calvin were trained by Renaissance humanist philosophers), it would not be true that the main force of liberalism in the Church and religion in general is humanism.
I put that in contrast with Steven Pinker quote below (from the episode “Steven Pinker vs Nick Spencer • Have science, reason and humanism replaced faith?” of the show “The Big Conversation”, by Premier Unbelievable, online June 2018, around 3rd minute):
Journalist: Obviously in the book you make the case that science, reason, human are largely responsible for this progress. To what extent do you see Christianity, religion in general, as being a help or a hindrance in the progress ?
Pinker: (…) The institutions evolve, including religious institutions, including some but not all Christian denominations, and if institutions I think largely under the influence of Enlightenment values back off from the literal supernatural beliefs, back off from the iron age morality in a lot of the Old Testament such as capital punishment for homosexuals, and begin to align their goals with humanistic ones, then they can be a force for tremendous good by mobilizing communities, by encouraging altruism, but it depends very much on the extent to which each institution commits itself to humanistic values.
Question: This is how I would like to open this topic and question. What is the main source of humanism in religion? By “humanism” I understand here Reason, science, autonomy/individualism.
Disclosure: Deirdre McCloskey described herself as a “postmodern free-market quantitative Episcopalian feminist Aristotelian” (her website).
 Not saying that this is the only form of humanism, let alone the only form of humanism allowed to exist.