After embracing deism, which is defined as the
belief in the existence of a God on the evidence of reason and nature only, with rejection of supernatural revelation. (Dictionary.com; Random House Dictionary)
and having persuaded others to deism, Benjamin Franklin concluded that good works and an intention to help others was necessary to good behavior and a moral society.
Franklin changed his mind regarding the efficacy of strict deism, which is based on reason and nature only, when he was harmed by two individuals whom he had persuaded to embrace deism. Afterward, he began to question his own actions and wondered if he had not acted similarly toward others, in particular Deborah Read. As a result, Franklin modified his beliefs so as to include the statement that the best way to serve a deistic God was to do good works and help others. His test of deism then boiled down to whether it was useful to society and to individuals or not and he concluded that, though possibly true, strict deism unmodified by good works and helpful intentions was not useful.
Franklin was a pragmatist who measured philosophy and actions by usefulness; usefulness itself measured by outcome and consequences. This set him in direct opposition to Calvinism and the Puritan Calvinists.
For more information, read an excerpt under the heading of Calvanism and Deism from Chapter Three of the biography Benjamin Franklin: An American Life by Walter Isaacson (Simon & Schuster) available at BookReporter.com.
In his autobiography, he states: "I concluded, at length, that the mere speculative conviction that it was our interest to be completely virtuous, was not sufficient to prevent our slipping; and that the contrary habits must be broken, and good ones acquired and established, before we can have any dependence on a steady, uniform rectitude of conduct"
In other words, you must break bad habits and establish good ones to achieve moral perfection.