Shock! Samson Agonistes is obsessed with religion. Okay, now that you've recovered from that mind-blowing announcement, let's check out exactly how this theme gets deployed: lots of talk about God; pretty much everyone spends their time talking about religion; and, oh yeah, it's based on a Biblical story. But religion isn't just a superficial spackling. Milton is asking some serious questions here: What's the right way to be religious? What's the right religion? How can religion or the divine help you understand what right and wrong are? We think it's proof of just how serious Samson Agonistes is about religion that it doesn't offer any easy answers to these big questions. Instead, it just puts them out there for you to decide.
Even though the characters in Samson make a big deal about whether they're Hebrew or Philistine, they all seem to act in the same way. Religion doesn't seem to make a big difference after all.
Considering how this story ends, Milton is trying to show religion's dangers, not its benefits.