Carrie Underwood was greeted by screams on Monday evening (Jan. 2) when she surprised college students at the Georgia Dome during an unannounced performance. The country superstar joined Christian singer David Crowder on the stage at Atlanta's Passion 2017, an evangelical conference for college students.

The singer joined previously announced acts like Chris Tomlin, Hillsong United and Matt Redman for her one-song set.

For nearly four minutes, Underwood grabbed the audience's undivided attention with a powerful performance of her No. 1 song "Something in the Water." Dressed all in black, Underwood's pipes soared as she sang her chart-topper, which includes a snippet of "Amazing Grace," for the 50,000 in attendance.

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"Something in the Water" was a crossover hit for the star, reaching No. 1 on both Billboard's Hot Country Songs and Hot Christian Songs charts in 2014. It spent seven weeks at No. 1 on the Country Songs chart and an incredible 26 weeks on the Christian chart, and went on to win a Grammy Award for Best Country Solo Performance. "Something in the Water" was featured on Underwood's Greatest Hits: Decade #1 album and was co-written by Underwood, Chris DeStefano and Brett James.

Underwood's unannounced performance at Atlanta's Passion 2017 kicked off the three-day convention. The crowd was more than overjoyed that the singer took the stage, and so was Underwood, who shared her appreciation to the audience and Crowder on Twitter.

“It’s really kind of a joyous, uplifting song about changing your life for the better and kind of having that ‘a-ha’ moment, to waking up and your life being different from that moment forward,” Underwood said of "Something in the Water" during an appearance on the Today show.

Though she works primarily in a secular format, she doesn’t worry that speaking out about her faith will alienate her fans.

“Country music is different. You have that Bible Belt-ness about it,” she said in 2012. “I’m not the first person to sing about God, Jesus, faith [or] any of that, and I won’t be the last. And it won’t be the last for me, either. If you don’t like it, change the channel.”

Watch Carrie Underwood's Most Unforgettable Moments