"He's just such a lovely actor and such a great guy. It was an absolute pleasure," Robertson said of Apa.
While speaking with TooFab at the movie's press junket, the actress, 29, opened up about filming the faith-based drama alongside Apa, who she also starred alongside in 2017's "A Dog's Purpose."
"It was good. Yeah," Robertson said with a smile. "I mean it's always nice being able to work with your friends. So to know that this all kind of happened in a way that you are going to get to work with your friend for the next like two and a half months in a place like Mobile, Alabama. It was like a dream come true."
She added, "Also, he's just such a lovely actor and such a great guy. It was an absolute pleasure."
Since "A Dog's Purpose" and "I Still Believe" are both very emotional films, we asked Robertson how she was able to pull herself out of that dark head space after filming.
"Well, it helps having your buddy," she said. "It's nice to be able to walk away from a hard day at work and just be able to kind of decompress and talk about personal stuff or just sort of sit and in silence even, you know. So that was really nice. Just having someone that I enjoyed being around and being able to just take a deep breath."
A true story of hope, love and loss, "I Still Believe" follows Christian music singer Jeremy Camp (Apa) and his romance with his first wife, Melissa (Robertson) as she battles ovarian cancer.
Robertson also spoke about how her personal views on faith were impacted after starring in a Christian film.
"Well all of it was so influential," she expressed. "And as I've grown and as I've moved to different places in the world and I've just experienced so many different things as I'm growing as an individual and my faith has definitely changed and evolved. But this film in particular has made an impact more than anything else I would say."
When asked what she'll take away most from the experience, Robertson said working on "I Still Believe" has changed her outlook on life.
"It's given me just greater understanding for having compassion, having perspective on your life and being able to take advantage of the things that you can enjoy right now in this moment," she recalled. "I think before doing a film like this, before meeting Jeremy or hearing their story, I was so like la-di-da like, let's go about life."
She continued, "And after this film you kind of go like, la-di-da, like what a great life, you know, and you sort of start taking inventory of all the great things that you take for granted, like your health or whatever it may be."
TooFab also spoke to Christian singer, Jeremy Camp -- who Apa plays in the film -- and expressed what he would say to those who may be hesitant to see a faith-based film. See how he answered the question and more from Camp in the full interview, below.
"I Still Believe" hits theaters Friday.
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