I'm an amateur religious studies buff and religious studies major. My impression of the three major Abrahamic faiths (ie Judaism, Islam, and Christianity) is that religious tolerance (not outright wiping out all religious minorities) was more or less grudgingly accepted in Abrahamic traditions. But religious acceptance, ie the idea that no one should face second class citizenship or discrimination for their beliefs does not seem to factor in to the thought processes of faith thinkers until fairly recently.
I've recently taken a class on interfaith cooperation. Nowadays many religious leaders support full religious tolerance/acceptance, but this seems to be a relatively modern thing and I was wondering what the roots are?
Noel Johnson and Mark Koyama have just written a book on that topic, "Persecution and Tolerance: The Long Road to Religious Freedom," from the perspective of institutional economic history.
To summarize: Their idea is that, when states are relatively weak and have little in the way of administrative power, they tend to use what they call "identity rules," where your rights are assigned to you based on what group you belong to. (Are you a peasant, or a lord? Are you a Christian, or a Jew? Are you a man, or a woman?) These rules are a cheap and easy way to govern. You don't necessarily need to understand the details of crimes, negotiations, agreements and so on, you just need to identify who is who, and mete out "justice" accordingly. But this method is also undermines the construction of more sophisticated forms of trade and interaction; if the legal system just sees an individual as an extension of their identity, then they cannot have the sorts of legal rights necessary to engage safely in exchange and investment.
Religion is also a convenient way to legitimate a ruler or governing system. By making an alliance with particular religious authorities with a broad following, a ruler could use religion as a tool of governance. Leaning on a particular religious idea for legitimacy was cheap, and did not require nearly so much state capacity as enforcing governance through force, and did not involve diluting state authority by enfranchising a class of citizens. All this can and did endure as a stable social order in many parts of the world.
But centralizing states have good self-interested reasons to push back against the use of identity rules and religious legitimation. For one, it supresses taxable economic activity. Group rights are not efficient for individual economic activity. If you protect an individual's rights to property and safety without overt discrimination by the courts, then this expands the pool of people with whom merchants, workers and investors can transact. For another, identity rules create sub-groups loyal to each other, and who might impede or compete with the direct authority of the state. This might be an acceptable price for a ruler worried primarily about being seen as legitimate, but not for an expanding state eager to amass resources and ensure loyalty for the fight against external threats.
As states became larger and competition among them more ruthless, extending religious tolerance was a method of increasing the power of a state, part of the process of forming modern nation-states. Not to say this was a one-way process, as there was substantial back-and-forth; persecution could still be a tool of the state, which had short-run (if not necessarily long-run) benefits. But those areas that generally embraced religious tolerance tended to be those with powerful, activist states, and who became richer over the course of the early modern period.
Whether this is the correct story is not certain, because tolerance is a complex, emergent phenomenon. I find the link with expanding states, the deliberate construction of a more thorough sovereignty over people and territory, and the suppression of competing sources of power and legitimacy to be compelling. At the very least it does not require believing that anyone just got more enlightened or tolerant for purely social or philosophical reasons. Tolerance becomes a product of state building, which is a very realpolitik sort of process driven by the demands of power.
Of course, the authors have their perspective. George Mason University is a fairly right-wing place, and the discourse there emphasizes narratives of individual liberty as a fundamental prerequisite to economic growth. I have generally found Mark Koyama to be a reasonable historical scholar and not a political fanatic (Noel I do not know), but one need look no further than the blog on the authors' website to see (for instance) their relative position on Hayek (whose insights they build on) vs. Marx (who they excoriate for anti-semitism). Whether that seems like a reasonable stance or not likely depends on one's own political priors.