Christian voters in the United States could find themselves facing a moral dilemma in November in case they will have to choose between Donald Trump and Hillary Clinton to govern the world's strongest nation for the next four years.

This huge dilemma is looming even larger as the two candidates continue to gather steam that could climax in a November 2016 U.S. presidential showdown.

With this in mind, Albert Mohler, the president of the Southern Baptist Theological Seminary in Louisville, Kentucky, is urging Christians to prayerfully consider how to approach this "unusual challenge," The Gospel Herald reported.

During a podcast briefing on March 2, Mohler said the likely contest pitting Clinton against Trump "is going to raise a host of new worldview issues with incredible urgency for confessing Christians."

He said "at the very least this is going to require of conservative Christians in America a fundamental rethinking of what we believe about the purpose of government and the character of political leadership."

Mohler said Christians must consider which of the two candidates exhibit "biblical fidelity and gospel faithfulness."

Trump has been labelled as a "fake Christian" by some religious leaders while Clinton has also drawn criticism for her support of abortion and same-sex marriage, two issues that go against biblical teachings.

"We're going to have to spend a great deal of time thinking and praying together about what faithfulness will look like in a way we never have before in terms of recent American presidential cycles; indeed, in a way that has never been true in this sense before in American political history," he said. "We're also about to find out if biblically minded Christians in this country are up to that task."

Mohler noted that the November election could see an "unusual challenge" since Clinton is running as a "Democrat of Democrats" while Trump has been widely criticised for his failure to show the true ideals of the Republican Party.

"The impending crisis in the Republican Party is one of basic conviction, vision and partisan identity," Mohler said, the Baptist News reported. "The Republican Party is going to have to face some very difficult questions about what exactly it intends to represent in the fall campaign if Donald Trump is the standard-bearer for that party."

Russell Moore, another prominent Christian leader, is strongly against Trump and has criticised evangelical leaders who support him despite the latter's penchant for using profanities aside from other character issues.

Moore, the president of the Southern Baptist Convention's Ethics & Religious Liberty Commission, has also condemned other evangelical leaders for "looking the other way" in regards to Trump.

"Why are many evangelical leaders, including some who pontificate on nearly everything else, scared silent as evangelicalism is associated with everything from authoritarianism and bigotry to violations of religious freedom?" he asked. "How can they look the other way in silence when politicians praise Planned Parenthood and demur about white supremacists and neo-Nazis?"