He told CBBC Newsround's website at Birmingham's Box Live gig that Girl In The Moon is "about the idea that we have all got a guardian angel".
"I'm lucky because I've got a whole bunch of them," added Darius, who has just finished a sell-out tour even though he was booted out of both Popstars and Pop Idol.
"People always ask me why I came back and what got me through - this song is about that.
"I turned my life around because the public gave me the support to pursue my dream."
Darius has been thanking his fans by inviting one of them on stage when he performs the song.
Darius sang to eight-year-old Julia from Kenilworth at the Box Live gig in Birmingham on Thursday.
"It was brilliant - I couldn't believe it," said Julia.
Her mum revealed Julia had been praying that Darius would pick her.
Looks like her prayer was answered!