Hawaii is like the rest of the United States in the way that it doesn't have one set religion. Although the population is generally of Christian belief, that leaves room for Catholics, Baptists, Methodists, stc. But, there are many other religions there. There are Polynisian religions, Jewish people, and just about every other kind of religion you can imagine. There is not a rule or expectation for religion in Hawaii and in fact, many people there are absolutely no religion at all.
So, if you are going to visit or move to Hawaii and have a certain type of church you'd like to attend or religion you'd like to practice, you are sure to be accomodated and not judged. In essence, Hawaii is consistent with the rest of the United States in being all about freedom to choose when it comes to such matters as religion.
Traditionally, Hawaiians were polytheistic and animalistic and there are still many believers in spirits and magic there. However, nearly half are committed to a religion Buddhism having the largest following. Asian peoples predominate in Hawaii so not only Buddhism but Shinto, Hinduism, can be found and a surprisingly large number of Mormons. There are also plenty of catholics and some protestants.