Whether people like it or not, most polynesians have very similar religious views.
The polynesian islands had some crazy cultural practices in pre colonial times that involved very structured belief systems, and this was largely replaced by pretty extreme christian beliefs, spread by missionaries from Mormons, Seventh day adventists etc.
If you interviewed the polynesians playing Rugby League around the world, most would refuse to discuss their views, but they would mostly be in lock step with Izzy.
The only difference between Izzy and a few hundred other high profile RL players of polynesian heritage is that Izzy won't stay silent about his religious beliefs.