Bush explained once in an interview why she gave in and changed the name of the song (via Wikipedia):
"I was trying to say that, really, a man and a woman, can't understand each other because we are a man and a woman. And if we could actually swap each other's roles, if we could actually be in each other's place for a while, I think we'd both be very surprised! [Laughs] And I think it would lead to a greater understanding. And really the only way I could think it could be done was either... you know, I thought a deal with the devil, you know. And I thought, 'well, no, why not a deal with God!' You know, because in a way it's so much more powerful the whole idea of asking God to make a deal with you. You see, for me it is still called 'Deal With God', that was its title."
"But we were told that if we kept this title that it would not be played in any of the religious countries, Italy wouldn't play it, France wouldn't play it, and Australia wouldn't play it! Ireland wouldn't play it, and that generally we might get it blacked purely because it had God in the title."