For many dedicated church-going Americans like Rentz, their faiths and the teachings of their religious leaders have helped shape their personal political landscapes.
While polls show the economy tops voter's concerns ahead of the November 2 election, social and moral issues still influence the decisions many of the country's citizens make in the voting booth.
"Religion has always been central to American politics," said Robert Stein, a political science professor at Rice University.
Even when religious leaders shy away from directly endorsing candidates, they have a strong influence over their flocks, and are particularly adept at getting their parishioners to head to the polls, he added.
But pastors tread a fine line when preaching about politics from the pulpit in the United States because churches and other tax-exempt organizations are prohibited by federal law from endorsing candidates or getting directly involved in elections.
Purdy, like scores of other religious leaders who speak openly to parishioners about political issues, considers the restriction to be an irrational violation of his freedom of speech.
"I don't see how one can stand in the voting booth and separate themselves from faith," said Purdy, who has been the pastor at First Baptist Seabrook for almost a decade.
Purdy has seen more of his congregants ask for support on making political decisions this election year than any other.
"And it's my place to tell them how the Bible speaks to it," he told AFP after Sunday services.
Purdy was one of nearly 100 pastors nationwide who participated in the third annual Pulpit Freedom Sunday on September 28 in which pastors openly violated the law by directly endorsing candidates.
Sponsored by the Alliance Defense Fund, a conservative Christian legal group, the event was aimed at challenging the Internal Revenue Service, in hopes of sparking a legal battle on the constitutionality of the law enacted in 1954.
"I am a citizen inside the church as well as outside the church," said Purdy, who endorsed Republican incumbent Rick Perry for governor that Sunday.
The protest has yet to spark a reaction from the IRS, which only rarely revokes the tax-exempt status of churches which cross the line.
"Churches tend to be a lot more popular in America than the IRS, so they don't want to get into a pissing match with religious communities," said Richard Murray, a professor of political science at the University of Houston.
The lines are also sufficiently blurred that it's easy for religious to usher congregants in a voting direction without directly endorsing candidates from the pulpit, Murray said.
Many of the members of Purdy's church said they vote according to what is taught by their pastor and the Bible.
They said they appreciate politics being discussed during services and that it helps them become more informed about the stances of candidates.
"I think it educates the congregants on things that are going on that they do not come across on a day to day basis," said Stephen Foster, 36.
Melissa Cameron, 29, said that while she's worried about the state of the economy, she thinks it's more important to vote for candidates that shared her views on social issues.
And she wants her pastor to help her understand where the various politicians stand.
"It helps me to know what exactly the Bible says on the issues, rather than what politicians have to say," she said.