HELENA - The Mark Wahlberg movie “Father Stu,” which is based on the life of Helena priest Father Stuart Long, is returning to theaters this week.

But they never married. When Long was baptized, he felt called by God to the priesthood and remade his life, teaching at Catholic schools in Mission Hills and then New York before getting a Masters's degree in philosophy.

That's the first of two major turning points in Stu's story. One thing leads to another for Stu, and before you know it, the film ends with him becoming an ordained Roman Catholic priest in his birthplace Montana, USA.

In "Father Stu," in which the Oscar-nominee plays a boxer-turned-priest, he gained 30 pounds to portray Stuart Long towards the end of his life when he had a rare autoimmune disease called inclusion body myositis.

The film, starring Mark Wahlberg and Mel Gibson, is based on the true story of a boxer turned priest and explores how humility is the price you must sometimes pay for success.

Wahlberg was inspired by Father Stu's life - how after a sinful life, he found redemption in faith in Christ and spent the rest of his life showing to others the grace that God had shown him.

Played by Mark Wahlberg, Father “Stu” Stuart Long died at the age of 50 in 2014 from a rare muscular condition. He was ordained a priest in the Diocese of Helena in 2007. A late vocation, Long had pursued careers in acting, boxing, teaching, and museum management before entering the priesthood.

His younger brother Stephen died suddenly of infectious meningococcus, just before he turned five. Stu was 9 years old at the time. Stephen's death was rough on the whole family, and led to some dark times. But overall, Stu's childhood was a very happy one, Amy said.

During seminary, Fr Stu had hip surgery wherein a fist-size tumour was discovered. He was diagnosed with inclusion body myositis, an inflammatory condition in the muscles for which there is no cure. His body was already slowing down when he was ordained to the priesthood in December 2007.

"I was just turning 50 by the time we finished the movie, and I was eating 11,000 calories a day. That drastic weight gain really took a toll on me over the course of the last seven, eight months." Mark Wahlberg says his 'Father Stu' weight-gain transformation 'really took a toll' on him.

Wahlberg saw similarities between his life and Long's with 'trying to find your purpose in life' So all this started because a priest from your parish pitched you a Stuart Long biopic.

This life, no matter how long it lasts, is a momentary affliction preparing us for eternal glory. We shouldn't pray for an easy life, but the strength to endure a difficult one. Because the experience of suffering is the fullest expression of God's love. It is a chance to be closer to Christ.

Stephen Farber of The Hollywood Reporter says the movie succeeds in not being sanctimonious, but it's also not quite as compelling as they might have wanted. He says despite some R-rated language, Father Stu seems bland and perfunctory, and its script is rushed and unconvincing.