Puritans left Europe to escape religious persecution. How did they treat people in colonial New England whose religious beliefs differed from theirs?

The exact same way that they had been treated before they migrated.

The Puritans were ruthless when it came to people with competing religious beliefs. Not only did they condemn the religions of their Native American neighbors, but they even thought that Catholics, whom they called "Papists," were worshippers of a false religion.

When one Puritan tried to establish a separate religious movement at a place called Merrymount, the Puritans actually assembled a military force to invade that settlement and destroy it.

Still another example of Puritan intolerance is the existence of the state of Rhode Island, which was initially founded by people who had been kicked out of the Puritan settlements of Massachusetts because their religious beliefs were not accepted there.