Yes, but that's very normal, because these are the things that are important to him.
Artists - writers, musicians, painters - use their favourite motives over and over again in their work.
Since I'm a writer myself, I know how close some motives can be to you, you just want to use them in almost every piece you write.
But I think we should not forget here that Mercy hasn't been released (yet). Bono often uses lyrics in a certain version of a song or a demo and then puts them into a song on an album, like he did with the much loved and hated "freedom has a scent" thing in Levitate and Miracle Drug.