I did a lot of work on this subject while get my MA. I have seen this movie before and I have heard Barton before. The truth is actually in the middle. Many founders were followers. In fact in most states following the birth of the nation one had to be involved in church in order to get elected. In fact more than half the states had state ran churches. The founders were primarily of the reformed theology (Presybeterian and such) There were some who were deist and some who were agnostic. Of the original signers of the DOI all but 2 were active in their church. However as we all know being active in church makes you a followers about as much as working in a garage makes you a car.
So take the video and anything you hear from Barton with a grain of salt and realize they have a personal agenda and a per-disposed hypothesis. When doing historiography it is very easy to read the sources that fit your views and ignore the one that do not. Both of them did that. I got to read the works of just about every player in the founding of America and I learned a lot of what I thought was true was not so much.