What did the Puritans believe?

The Puritans wished to purify for cleanse the Church of
England, which was steeped in religious traditions similar to the Roman Catholic
Church.  The Puritans wanted to return to a stricter moral code based on the teachings
of John Calvin.  Instead of basing their religion on the ritualistic traditions of the
Catholic Church Puritans turned to John Calvin's teaching, and so the Puritan belief was
that through their good works they would be able to achieve salvation. It was this
covenant (or promise) that the Puritans believed was made with God that lead a certain
select elect group of chosen to be leaders within the church.  Their beliefs
also allowed church elders, leaders of the church who were not ordained ministers, to
rule over all aspects of Puritan life- including domestic incidents. Puritans had strict
rules against any frivolity that took away from their good works for God- including
dancing, singing, drinking, card playing, and other such "immoral
acts."

Puritans churches were plain, simple meetinghouses
void of any ornate furnishings.  Church met several times during the week, but Sunday
service was the main event including a two hour sermon and hymns sung without musical
accompaniment.

Look to examples of Puritan sermons like
Sinners in the Hands of a Angry God, linked below, to see Puritain views on hell and
brimestone.  The Puritains truly belived they were the only path to heaven, and beliving
anything different would most certainly lead to a firey, hellish after
life.