Noel has spoken of the song in two different instances:

For about three months, we all thought that song was called ‘Guess God Thinks I’m Able,’ as in an able-bodied man. “So we’re coming to write the track listing one day and [Liam] goes, ‘It’s not f—ing "Able,” it’s “Abel,” ’ and he wrote it out and we were all kinda looking at each other, going, ‘Hmmm.’ I had to go back and listen to it, and then I was just sat down thinking about it and the story of Cain and Abel. I’m thinking, ‘Well, that’s very religious and biblical and it’s a bit deep.’ But … the first line of the song is ‘You could be my lover’ which … you’d have to speak to Liam about. He has a religious fixation with [Abel] and Jesus, I think. It’s very strange.

and:

Liam’s gotten all religious. It’s quite disturbing. He thinks he’s Abel for some weird reason. He wrote a new song called “Guess God Thinks I’m Abel.” And I thought, “Right, so you think you’re Abel. That must make me Cain. Doesn’t Cain kill Abel?” But then the first line of that song is “You could be my lover.” I’m not too sure about that. That’s illegal, innit? It’s kind of illegal for two brothers to make love. It’s certainly frowned upon.