"Duck Dynasty" stars Willie and Korie Robertson are never afraid when it comes to expressing their Christian faith.

"God and our faith is what sustains us," said Korie Robertson to FOX411. "It's what makes our life good."

The reality series stars have their very own platinum Christmas album, books on the New York Times bestseller list and currently the couple made their film debut with an appearance in the upcoming movie "God's Not Dead."

The duo revealed the mystery of the Robertson family's success.

"God's blessed us with a lot of opportunities at this point," said Willie Robertson to FOX411. "Just like the movie 'God's Not Dead,' there's that element of faith that you have to have faith."

In the upcoming movie, Willie and Korie stars as themselves in a scene where they are harassed outside of church by a reporter who asked them how they feel about people who say they do not like the prayer scenes on the A&E show. 

"We're not trying to offend anybody," said Willie to the reporter in the movie. "As far as my praying to Jesus, my life and my whole eternity belongs to God. The money, fame, success, temporary. Even life is temporary. Jesus, that's eternal."

Willie and Korie said the scene rang true to them, as the Robertson family is used to having to defend their faith.

"I think in our everyday lives there's always this opportunity to explain your faith to people who are not believers and people want to know how you live your life," said Willie Robertson to FOX411. 

Despite the fact the Robertson family are never ashamed to express their strong faith, the couple revealed that they don't force their viewpoints onto other people. 

"We don't feel like we're shoving any religion down anyone's throats," Willie to FOX411. "We're just being ourselves, it's positive. To us, just saying a prayer at the end [has had] a huge impact, but in our lives saying a prayer's not that big a deal. We do that all the time."

Korie Robertson echoes her husband's sentiments.

"Don't let someone bully you into not standing up for your beliefs," said Korie Robertson in a recent FOX411 article. 

"God's Not Dead" was directed by Harold Cronk, and stars Kevin Sorbo, Shane Harper, Dean Cain and David A.R. White. It will be released in over 700 theaters throughout the United States, hitting the big screen on Friday March 21 by Pure Flix Entertainment.

The critically acclaimed reality series Duck Dynasty airs on the A&E network on Wednesdays at 10pm EST.