Why did Americans think the spread of democracy was divinely blessed?

I suppose that this about Manifest Destiny. At that time, America had entered a time that was relatively prosperous and they were intensely patriotic. Plus, religion played a big role in everyone's lives. Put these two things together and then you have Manifest Destiny. Westward expansion was on the minds of everyone, for they needed the land and the money. The divine right of expanding democracy served as an incentive, among others, to move outward.