When studying religions, one simple classification is between “Universal Religions” and “Ethnic Religions.” There are religious perspectives that don’t clearly fit into either, but these two are useful categories.

Universal religions are a system to identifies with all people. As such, there is an evangelistic component normally. Ethnic religions, on the other hand, identify with a specific people group or governance. As such, there is a low evangelistic component. In some such groups, it may even be forbidden for outsiders to become part of it.

Not all religions fit clearly into these two, and there are many that sort of bridge the gap. Judaism was (and is) often seen as more as an ethnic religion. There are proselytes, and some members may even be somewhat evangelistic, but the efforts are rarely vigorous. Members of the Samarian Israelite faith originally actively prevented outsiders from joining, but that has relaxed somewhat in recent years. Traditional mystery cults were not evangelistic as this is commonly pictured, but they were open to selective recruiting.

But I always struggled with ethnic religions. For me, I tend to think about religions as answering the great questions of life. Who am I? Why am I here? What is our future? Do I need to be saved/rescued, and if so, how? These are universal questions. For me, then, if they give answers to universal questions, then the answers should be universal answers. And if that, how could adherents to that faith be comfortable about keeping those answers to themselves only.

I kind of knew the answer, but reading Nijay Gupta’s book, “Strange Religion,” he looked at Christianity through the lens of Roman State Religion (I suppose I could use “RSR”) for short. Gupta notes that RSR was not so much about faith, or about beliefs. It also, generally, was not about ethics, or a relationship with the divine. The two PRIMARY functions for RSR was:

• Pax Deorum. This is Latin for “peace with the gods.” Rituals and sacrifices were done, first of all, to maintain a peaceful coexistence with the supernatural world— the gods who can be benevolent or malevolent, depending on how well we treat them.
• Magic. We are not talking about legerdemain here, we are talking about doing things so that we can manipulate supernatural beings or forces to work for us. Rituals, sacrifices, amulets, talismans, and more can be used to seek blessings, or to give curses.

Suppose, you were a Roman, you are pretty sure you want everyone who lives within the borders of your empire to practice the rituals and sacrifices of RLR. You don’t care what people believe. You don’t care what people do particularly, as long as they do the bare minimum to appease the gods so that they support the peace, and strength of the empire. As such a Roman, you would have little interest in the German tribes, or the Parthians, sharing the same religion. In fact, you might not really want them to do that at all. If they are the enemy and they start doing things to curry favor from your gods, what if your gods start to support your enemy? Really, you want only people in your group to be the ones who know how to keep your gods happy— in fact, keep your gods as YOUR gods.

A similar things applies to magic. You want the special favor and the blessings of your gods to be on you, and your friends, and perhaps your countrymen. You certainly don’t want them to be helping out the enemy.

Christianity, while not, strictly speaking, wholly unique in its initial setting, was pretty revolutionary in the Roman Empire. Its view of religion tied to relational devotion to God, faith/belief, and addressing universal questions, with universal answers, put it into a place that unique place— in a world where religion was commonly FAR different.