The world of Casting Crowns frontman Mark Hall was rocked last year after he found out that there was a solid mass in his right kidney that doctors said was cancerous.

"It was definitely out of nowhere," Mark Hall says in "The Church Boys" podcast. "I went to the doctor to be checked for acid reflux. He was just doing a scan to see if I had ulcers or anything else going on down there, and then, on accident, saw a tumour in my kidney."

Hall considers it an act of God that the tumour has not spread to the kidney surrounding it. Still, there was a chance the cancerous cells could grow rapidly.

"For a day there it really rocked me," he recalls. "I was going through feelings and doubts and fear and worry... my feelings were all over the map."

As a youth pastor, Hall was used to giving people comfort during troubled times. But when he was diagnosed with cancer, Hall found himself needing emotional support.

The singer is grateful that God never left his side throughout his whole cancer ordeal, and his faith took care of him.

"My feelings kept slamming up against something solid in me, and that was the roots of my faith," Hall says.

One thing Hall learned from that experience is that God is who He says He is. He was inspired to create new music while dealing with cancer. That's the time when he wrote the song "Oh My Soul." Hall shares that it is all about Psalms 42:5 which reads, "Why, my soul, are you downcast? And why are you disquieted within me?"

"The night I found out, I sat down at the piano and wrote a song called, 'Oh My Soul' around that Scripture, because that's kind of where I was living at the moment," he says.

Thankfully for Hall, his cancer battle had a happy ending because doctors were able to remove his kidney where the cancerous cells were attached. "God is who He says He is - and we can trust Him," Hall says.