Why is it that the Spanish and the Portuguese were more successful in spreading the Christian faith than the English and the Dutch? Was it because the English and the Dutch did not proselytize, or the Spanish and the Portuguese were simply more successful?

The Dutch did not really push for settlement. They saw their exploration mostly as a business. The Spanish and Portuguese saw it more as colonization. One of the big examples would be Albany. It was very very small. It was not a major development. And they wanted to keep it very small so there would less competition. It was not till much later they decided to give away land to some people and you had some development such as in Rensselaer. Even the city of new Amsterdam was very very small. They were all about the money.

A good source is the book Conceived in Liberty which is available online if you search. It has excellent chapters about the Dutch exploration and the differences between the Spanish, the Portuguese, the Dutch, and English.