I don't think he is talking about Christian girl he used to date that moved further and further out of the picture as Fionar2001 suggested, but actually God Himself that he is moving further and further away from. As he gets closer to the devil, he looses touch with God. The devil he could possibly be talking about may be abusive habits like alcoholism or drug addiction when he says
"You know the devil only holds a lease
And he's so hard to kick, man
It's been twenty years since I've been clean"
or maybe just other bad habits that he just can't seem to give up. And when he says
"Maybe I'm losing sleep over nothing"
he means that he is stuggling with this internal conflict of whether to embrace God or the devil's ways; however, at the same time he isn't completely sure God even exists and maybe he is just wasting energy thinking about it.
I don't think he is talking about Christian girl he used to date that moved further and further out of the picture as Fionar2001 suggested, but actually God Himself that he is moving further and further away from. As he gets closer to the devil, he looses touch with God. The devil he could possibly be talking about may be abusive habits like alcoholism or drug addiction when he says "You know the devil only holds a lease And he's so hard to kick, man It's been twenty years since I've been clean" or maybe just other bad habits that he just can't seem to give up. And when he says "Maybe I'm losing sleep over nothing" he means that he is stuggling with this internal conflict of whether to embrace God or the devil's ways; however, at the same time he isn't completely sure God even exists and maybe he is just wasting energy thinking about it.