I think if you had let a little more of the light shine from behind the roof it would have had a more profound effect. Additionally, there's too much sky in the picture.
clearly fits the challenge in my book. But, to be honest, the shot does not hold a great deal of interest. There is too much of the plain blue sky and the light over the roof would likely have come off a lot better if it were behind the cross - emphasizing the theme you were going after.