I have always been fascinated by the history of religion. I think that understanding how ideas change, adapt, and in some ways stay the same is a fascinating thing to think about.
When I was in college, I started reading some of the early Christian apologetic books the Church Fathers). Not having much context for this, I started reading about the history of Christianity. What I learned (and there is still a lot I don’t understand) is that the Christianity which I met when talking to evangelicals was not the Christianity which existed in the first century. In fact, the Christianity of the first century was not the same as it was when Christianity became the religion of the Roman Empire in the 4th century. And considering how culture changes, the Christianity of 100 years from now will likely be very different than it is now.
Why does this matter? For one, knowing the origin of ideas you may or may not actually believe puts a human face on it. DO you realize that the Nicene Creed, and many of the doctrines which the Catholic Church has carried through history, were debated about, voted on, and many of the people who disagreed were ostracized, silenced, or killed. The doctrines of religion often come about due to political and economic concerns, and not some idealized philosophy or pure revelation. Understanding the historical context of ideas makes them real, natural, and human.
And yet people, in our culture today, often feel that these ideas come to them in a direct relationship with god. And if history had been different, or had they been born in another culture, they would feel the same way about another idea. The way a Christian feels while praying is much the same as a Muslim, Pagan, etc feels while they do their on rites and rituals. Those feelings have little to do with the specific belief system they hold.
Seeing the history of ideas shows how relative and dependent they are. When you see a religion in the context of history, you see how they are all similar and ultimately human, natural behaviors rather than truths from some divine realm.
I urge everyone to learn about the history of religion. And not only their own, but about other religions. Because if your religion is true, learning about it cannot make it untrue, right?