Time to address one of the most controversial topics on earth. The one you really would rather not talk to your grandparents about. Religion. For some of us it's a subject we tip-toe around for the fear that the person your talking to doesn't agree with your beliefs. Why would you be afraid to talk about what you believe? Pick one of the many examples of bad things that have happen: The Crusades, The French Wars of Religion, The Thirty Years War. These are all very real conflicts that were started over disagreements in religious beliefs.
Now, why was this post called modern view on religion in colonial America? Because one of the conflicts in the new world was religion. They thought, go to the new world (away from Great Britain) and start a new religion with "good" beliefs. Everyone will agree. It'll be just peachy, right? Well, no not exactly. They still had many issues with religion. The British were still trying to enforce a strict Christian religion on the american colonies.
Think of this situation like you're in 4th grade again. What did all the kids do when the teacher left the room to grab something? They now have the ability to pass that note, throw that airplane or whisper to their friends. In this case the teacher (Great Britain) has left the building completely and driven home. The Americans aren't as scared of breaking the rules if the person who truly enforces them is thousands of miles away.
In the end we all know things worked out, but we still have significant religion issues still. It's as simple as a rude glare. To connect this to my last post, we're still far from perfect or "completely free." We are not completely free until everyone here drops the self righteous act and realizes we don't really know anything for sure.