One of Slayer’s signature songs both concludes and gives its name to their most acclaimed album. Writers Kerry King and the late Jeff Hanneman have said it’s one of their favorite songs to play live, and it has been an almost permanent fixture in their live set lists for more than 30 years. Often, they perform in the midst of a rain of stage blood.

According to D.X. Ferris' book Reign in Blood, Hanneman explained,

It’s about a guy who’s in Purgatory ‘cause he was cast out of Heaven. He’s waiting for revenge and wants to fuck that place up.

King added,

The rest of the song explains what happens when he starts fucking people up. The lyrics ‘Return to power draws near’ is because he’s waiting to get strong enough again to overthrow Heaven. And then ‘Fall into me, the sky’s crimson tears’ is everybody’s blood flowing into him. So basically, ‘Raining Blood’ is all the angels' blood falling on him.