Whoa! The Freespace universe takes place around the 2300s; 300 - 400 years in the future. 300+ years ago today you are talking 1600s in historical times where the fastest thing on Earth was a horse and the printing press was your closest thing to a computer. You are talking about a time where people actually believed that Monarchs held divine right and others had no rights at all based on birth. A time where the biological cell had yet to be discovered and people could only guess what was on the moon. Medicine was a nightmare and the vast majority of people worked the land as farmers in a struggle to feed the population. Had we lived back then, I'm sure many threads on HLP might have resulted in dueling.

I could go on as I have only covered a fraction of the differences.
Safe to assume they are the same? Realistically, I think one thing that we must assume is that things are not the same. This is a society that has taken residence on other worlds, encountered other forms of intelligent life and broken the very fabric of spacetime itself. There is no doubt that such dramatic milestones would compliment a changing culture.
So, maybe there still is religion and maybe there is no longer religion but I think the one thing that is safe to assume is that one way or another the Freespace Universe is very different from our own.