Rev. Franklin Graham has said he is left "encouraged" following Thursday's Republican presidential debate on Fox News, as several of the candidates opened up about their Christian faith and promised to govern the country in accordance with Biblical principles.

On Friday morning, Graham, who is the president of the Billy Graham Evangelistic Association and Samaritan's Purse, took to Facebook to share his thoughts.

"The first GOP debate is over, with many more to come. I was encouraged to see several of the candidates express their faith in God and His Son, Jesus Christ. There's no question, 2016 could be the most important election in our country's history. Pray that God would raise up an individual to lead this nation," he writes.

"The Bible says that King David was a man after God's own heart. Even though he had failures in his life, God used him greatly to lead the people. God's Word says, 'And David shepherded them with integrity of heart; with skillful hands he led them,'" he continued.

On Thursday night, Fox News debate moderator Megyn Kelly asked the ten GOP candidates on behalf of a submitted question, "what has God been saying to you about running for president?"

Because of the large number of candidates, only five of them were able to answer, including Dr. Ben Carson, Senators Ted Cruz and Marco Rubio, and Governors Scott Walker and John Kasich.

"I am blessed to receive a word from God every day in receiving the scriptures and reading the scriptures," Sen. Cruz first responded. "And God speaks through the Bible...I would also note that the scripture tells us, 'You shall know them by their fruit."' We see lots of 'campaign conservatives.' But if we're going to win in 2016, we need a consistent conservative, someone who has been a fiscal conservative, a social conservative, a national security conservative."

Ohio Governor John Kasich was the next candidate to answer the question, stating, "We've got to listen to other people's voices, respect them, but keep in mind, and I believe in terms of the things that I've read in my lifetime, the Lord is not picking us. But because of how we respect human rights, because of that we are a good force in the world, He wants America to be strong. He wants America to succeed. And He wants America to lead. And nothing is more important to me than my family, my faith, and my friends."

Governor Scott Walker of Wisconsin gave the next answer, stating,"I'm certainly an imperfect man. And it's only by the blood of Jesus Christ that I've been redeemed from my sins. So I know that God doesn't call me to do a specific thing, God hasn't given me a list, a Ten Commandments, if you will, of things to act on the first day.

"What God calls us to do is follow his will. And ultimately that's what I'm going to try to do. And I hope people see it in my state, even in the big challenges I took on when I had over 100,000 protesters in and around our capital, trying to do what I thought was the right thing.

"It wasn't just how I took on those political battles. It was ultimately how I acted. Not responding in kind. Not lashing out. But just being decent going forward and living my life in a way that would be a testimony to him and our faith."

Senator Marco Rubio of Florida was then asked to respond to the question about God, as well as one about military veterans. "Well, first, let me say I think God has blessed us. I believe God has blessed our country. This country has been extraordinarily blessed. And we have honoured that blessing. And that's why God has continued to bless us... And he has blessed us with young men and women willing to risk their lives and sometimes die in uniform for the safety and security of our people."

Dr. Ben Carson, a retired neurosurgeon, then talked about God in the light of the ongoing racial divisions in America.

"I think the bully pulpit is a wonderful place to start healing that divide" he said. "You know, we have the purveyors of hatred who take every single incident between people of two races and try to make a race war out of it, and drive wedges into people. And this does not need to be done...

"Because our strength as a nation comes in our unity. We are the United States of America, not the divided states. And those who want to divide us are trying to divide us, and we shouldn't let them do it."

Other hot-button issues discussed Thursday night included Common Core, abortion, same-sex marriage, and immigration.