“Believer” thunders around a percussive backbeat and expressive vocals from Dan Reynolds to bring about a message of embracing pain, and using it as a tool for personal growth. It marks the end of Imagine Dragons' self-imposed hiatus that started in 2016. The song acts as the title for their documentary surrounding LGBT youth and the Mormon church.

The song was released on the first of February as the lead single for their third studio album, Evolve, and was featured in a commercial for the Nintendo Switch that premiered on Super Bowl LI. The song was also featured in the first trailer for Kenneth Branagh’s Murder on the Orient Express remake.

Nearly two years after its release, the band released a remix of the song alongside Lil Wayne during their 2019 National College Football Championship halftime performance.