Lyric discussion by Mikaela120 

Cover art for Empire (Let Them Sing) lyrics by Bring Me the Horizon

This doesn't really make so much sense, but I've always thought that the person in the song starts hearing voices. For example:

"We've been surrounded, by vicious cycles"

"I hear them clawing at the gates "Let us in, let us in" I hear them calling out my name (I don't care)"

and also the phrase

"Let them sing".

The theory about God makes much more sense, but when I heard this song for the first time, that was what I heard.