The contrasts and conflicting values interacted with what the colonists had in common to create an American society that was democratic and egalitarian.
What the colonists had in common was race and, in general, the desire to better themselves. This meant that they saw other colonists as roughly equal to themselves. No white person was better than another to most colonists.
What they did not have in common was things like religion and cultural background. What this did was to make them understand that people did not have to be exactly the same in order to be equal. It gave them a culture in which most differences between white people were seen as irrelevant. All white men were seen as equal and America became something of a democratic melting pot. This differentiated American culture from the more hierarchical and parochial cultures of Europe.