With a style initially similar to The Eagles and Lynyrd Skynyrd, Petra's sound evolved into a more energetic, driving rock sound in the early 1980s akin to Foreigner, Styx and Journey. Throughout the 1980s and into the early 1990s, Petra was one of the world's most popular Christian rock bands, with each of its albums during that period selling hundreds of thousands of copies while the band sold-out arenas and regularly placed songs at the top of Christian radio charts. With its lyrics, music and style, Petra influenced numerous other artists at a time when Christian rock experienced strong opposition from many conservative pastors and churches.