We all know the narrative, Newt is now a good old fashioned repentant Catholic. But if he lived during Biblical times, he would not have lived this long. Most reasonable people would agree that we do not want to use biblical law to rule our society. The fact of the matter is, our founding fathers did not want to live by biblical law either. Stoning counts as cruel and unusual punishment, and that was the normal way the death penalty was carried out during Biblical times.
Still, if Newt wants to have a country governed by religious virtues, maybe he should move to Iran or Saudi Arabia. I know those aren't "Christian" countries, but aside from a few small differences, isn't much of a difference between Christian religious law, and Islamic law. Both think Jesus is important. Both follow the Old and New testaments, and both worship the same God. Both think that anyone who doesn't follow their religion is damned to hell. The biggest difference is that Muslims can't eat pig or drink alcohol, and follow a prophet named Muhammad.
Also, he compared gay marriage to paganism, but last time I checked, members of so called pagan religions are allowed to get married in the United States. This is due to the fact that the First Amendment guarantees freedom of religion. Personally, I feel gay marriage should be legal, but if Newt's argument is that it shouldn't be legal because it is like paganism, he's going to have to take it a step further an ban pagan marriages too.