My dad grew up with Van Morrison in Belfast, NI and used to go see them play when they were first starting out as "them."
As far as I know, Van Morrison is a born-again Christian. My dad has all of his CD's and I know that he does a whole bunch of "Christian" stuff such as "Be thou my Vision" and there's #18 on the best of. He's a cool guy.
Music's a way of people expressing their feelings and I guess he's just expressing his love for God