One way of understanding the Second Great Awakening is in the context of sweeping social changes of the era. The United States was rapidly expanding, both territorially and economically. The Market Revolution changed the way many Americans lived, worked, and consumed things. It led to frequent economic busts and booms, and even posed a challenge to the structures of families. In the midst of rapid social change, people turned to religion. For many Americans, especially middle-class Northerners, this meant a shift to the individualism and the "perfectionism" of preachers like Charles Grandison Finney. For other anxious people, it simply meant that the fervor, more than the message, of tent revivalist preachers (who were mostly Baptists and Methodists) resonated with them. Still others, like the followers of Joseph Smith, the founder of Mormonism, turned to a faith that emphasized what they perceived as traditional values of patriarchalism and order. More than a few Americans embraced the utopian teachings of what we might call today "New Age" religious leaders.

The Second Great Awakening also cannot be separated from the political spirit of the age. This was a period marked by the democratization of American political culture. During the antebellum era, most states dropped property requirements. That shift allowed almost all white men to vote, while in many cases simultaneously stripping the vote from free black men. The message of many revivalist ministers was in many ways a faith tailor-made for this democratic age. Ministers stressed an individual's free will in bringing about their own salvation. They rejected in particular the idea of predestination and pointed to an individual's relationship with God. This new evangelism also de-emphasized the importance of religious training in carrying the message—many of the most popular revivalist ministers were not trained in seminaries.

Finally, we can perhaps understand the Second Great Awakening by taking the words of its adherents seriously. A constant theme in revivalist sermons was that the faith of the American people had lapsed. As one well-known minister put it in a sermon in the "Burned-over district" in western New York:

Now, many of this Church are in a cold state, I dare say. I don't mean to say they are worse than in other places, but I always find them so. My friends, how do you feel? I would ask you in a kind and affectionate manner: How do you feel? Have you lost the joy of your salvation—are you stupid and lukewarm?

There was a genuine belief among many religious reformers that Americans had turned away from their faith, or that religious belief had become superficial for most people. They thought, as a result, that the nation was overwhelmed by sin. This is also why the Second Great Awakening gave rise to so many reform movements. Many people saw slavery, drunkenness, and many other social ills as evidence that the American people had lost their way. In short, the Second Great Awakening was inextricably intertwined with the sweeping social changes of its day. The movement itself became a powerful force for change.

The Second Great Awakening was a rebirth of interest in religion that occurred in the late 1700s and in the early 1800s. During this time, people began to follow religion more closely by attending church services, going to revivals where people listened to preachers, and converting to Christianity. People began to feel that a void existed in their lives because of a disconnect with religious teachings. People felt that they wouldn't be judged based on if they attended church or lived their lives religiously. Also, more and more people were preoccupied with trying to make a living, which decreased their interest in religion. However, they began to realize that something spiritual was missing in their lives.

The Second Great Awakening also contained some of the ideas found in the American Revolution, as more opportunities existed for women and African Americans within the church and within religious life, which helped make religious observance more attractive to Americans.

The Second Great Awakening had a more positive outlook on life than the general dismal outlook that was portrayed within earlier religious teachings. It stressed that people had free will and weren’t subject to only being saved by G-d. Instead, it stressed that all people could take actions to change their lives for the better, which would lead to them being saved. This positive outlook encouraged people to view religion, religious practice, and religious teachings more positively.

The Second Great Awakening was in part caused by the Romantic movement, which was a reaction against the Enlightenment and its emphasis on reason. The Enlightenment had encouraged a religious movement called Deism, which emphasized rationality over emotion. The Second Great Awakening instead focused on encouraging an emotional and personal connection to religion and an emphasis on enthusiastic preaching. 

Religious revivals across the United States at the time spread evangelical religions and spread religions such as Baptism and Methodism. Many people believed that the world was ripe for the Second Coming, and, to prepare for this millennial age, many converts turned to reform movements to ready the world for the Second Coming of Jesus Christ. As a result, reform movements developed, including abolitionism, temperance, women's rights, and other movements. 

First, we must acknowledge that it is somewhat difficult and dangerous to try to say why religious changes occur.  When we try to find historical causes for religious events we imply that religion is simply made up by humans for their own needs.  A religious person might say, for example, that the Second Great Awakening occurred because of God touching people’s hearts.  If we are to be respectful of the beliefs of religious people, we must be cautious about attributing changes in religious beliefs to historical/social causes. 

That said, historians typically give two reasons for the Second Great Awakening.  First, they say that it got its start in the 1790s because religion was becoming too intellectualized in places like New England and because there were few organized churches on the frontiers.  People came to feel that something was missing from their religion because it was too intellectual.  Therefore, they turned to a more emotional brand of religion.

Second, historians say that economic changes contributed to the second wave of the Second Great Awakening.  This was the wave of the movement in which Charles Finney played a large role.  This wave was caused by economic changes like the opening of the Erie Canal.  These changes weakened social ties between people and made them long for something that would make them feel emotionally close to others again.  The emotional nature of the evangelical religion fulfilled this need.