What a way to kick off 2017.

If you were one of the thousands at the Passion 2017 conference at the Georgia Dome in Atlanta this week, you might have witnessed a very special surprise when Carrie Underwood walked into the stadium.

She was the unannounced performer who came onstage at about 9:30 p.m. Monday (Jan. 2) during the first night of the conference.

Underwood took the stage to join Christian artist David Crowder for a collaboration on “Lift Your Head Weary Sinner,” an original song he co-wrote with Ed Cash and Seth Philpott. Underwood also performed her “Something in the Water.” You can see from the fan videos that the crowd of roughly 50,000 people adored her.

She added on Instagram later that there was so much energy in the

room and that “these folks are changing the world!”

Crowder also shared photos of Underwood.

The Passion event is a college student movement that started in 1995, and according to its website, it is rooted in the confession of Isaiah 26:8.