A mid-tempo soul song, its lyrics detail Hozier's frustration with the Catholic Church and its stance on homosexuality.
The song was nominated for the Grammy Award for Song of the Year at the 57th Annual Grammy Awards.
The song has been certified five times platinum in the US.
Hozier, a struggling musician at the time of its writing, wrote and recorded the song in the attic of his parents' home in Bray, County Wicklow, Ireland.
The song spent 23 consecutive weeks at the top of the Hot Rock Songs chart, tied with Imagine Dragons' "Radioactive" as the longest-running #1 in its chart-history (at the time), later crossing over to the all-genre Billboard Hot 100, where it peaked at #2 in December 2014.