Carrie Underwood returns to Christian faith with new baptism-inspired song 'Something in the Water'

Carrie Underwood has gone full circle to cap a decade of hits with another faith-inspired song.

It's already been a decade since the country star exploded onto the music scene with her winning appearance on American Idol in 2005 and her first big hit, Jesus, Take the Wheel.

That song was all about a desperate mother's cry to Jesus to take control of her car and her life as they both spin dangerously out of control.

The song spent six weeks at Number One and landed a Grammy for Underwood.  

Although a Christian, Underwood has tended to take the subtle approach to expressions of her faith, and her music focuses largely on relationships and life through a lens anyone can relate to.  

But she's laid her faith on her sleeve once again with a new track, Something in the Water, that opens her soon-to-be-released album Greatest Hits: Decade #1. 

The lyrics of the powerful song include: "I followed that preacher man down to the river / And now I'm changed / And I'm stronger / There must've been something in the water." 

The song was co-written with Chris DeStefano and Brett James, and takes a leaf out of Jesus Take the Wheel's book in being about the power of faith to see people through difficult times. 

Underwood described the song to NBC's Today show as a "joyous, uplifting song about changing your life for the better and waking up and having that a-ha moment and your life being different from that moment forward". 

And she's clearly pleased with the track, tweeting today: "Just heard #SomethingInTheWater for the first time on the radio! Yay! So happy happy happy!!!"

It's been an incredible decade for Underwood and her greatest hits collection, which is set to release on December 9, will include no fewer than 18 number one hits.  

Underwood recently announced she is expecting her first child to husband of four years, hockey player Mike Fisher.  

She revealed last week she's still trying to get her round becoming a mom.  

"It's still kinda weird, to be honest," she said on the Today show.  "Sometimes I'll be with my husband, and it's like, I'm gonna be a mom.  You're gonna be a dad.  Is this real life?"