Prior to joining Petra in 1986, Schlitt was the lead vocalist for Head East until retiring from the band in 1980.

In 1972, he joined the rock band Head East as lead singer with some fellow students of the university.

After leaving Head East, Schlitt formed a short-lived band, "Johnny", with brother Jeff Schlitt, Don Colluci, Jim McNeely, Troy Tipton, Mike Willis and Burk Burkhardt, but the band quickly ended as his addiction intensified in a six-month depression during which he "came very close to suicide".

[4] During this time, Schlitt attended Gethsemane Church in Evansville, Indiana, where he sang with the praise and worship team.

Schlitt was also joined by former Head East drummer Steve Huston, along with the band's keyboardist Roger Boyd.

[6] Five years after Schlitt's departure from Head East, he received a call from Bob Hartman and was invited to audition for Christian rock band Petra.

The band had just lost its lead singer Greg X. Volz, who had left to pursue a solo career.

[11] In May 2008, John Schlitt toured India, playing eight dates in six cities with an all-new backing band, StoneJava.

With this new backing group, John played songs from his solo CDs, along with many Petra favorites, to positive reviews.

Hope That Saves The World made the top 30 on the Billboard and Christian Weekly charts in July 2012.

He has toured all over the world and has been inducted into the Gospel Music Hall of Fame as the lead singer of Petra.

Schlitt is the lead vocalist of a band, The Union of Sinners and Saints, with White Heart founder, guitarist and songwriter Billy Smiley.