Yeah I guess I could have gotten offended by the Christian angle but I didn't focus on that. They could have been singing about the Grinch or Santa or whatever for all I care.
There are so many surprises in this world, most of them unpleasant. I enjoyed the concept of a surprise of really good singers singing about happiness. I am very moved by music and how some much people care about it and how good some people are at it. I love vocal harmonies.
I have watched this about 4 times and it brings tears to my eyes.