Dear God, that video made me crack up. Please, Lord, say that it is a parody.
I personally am a Christian, although I really dislike the holier-than-thou attitude of many modern Christians, and cannot stand modern Christian "music", for the reasons listed above. U2 are Christians (except maybe Adam), and, of course, this has found its way into their music, more than most bands.
However, first of all, the greatest thing about Bono's lyric-writing ability is that what he wrote the song about is not necessarily what the song is about. Everyone is free to interpret his lyrics however they want, and, in the end, (barring saying that Mothers of the Disappeared is about sex or something) there is no right or wrong answer.
Bono has always been painfully honest about himself, and that is where my deepest respect for him comes from. I don't know him personally, and will never know what's really in his head, but my guess is that he has what I like to call Albus Dumbledore syndrome. He is a great man, greater than he gives himself credit for, and he's willing to freely admit his imperfections. He realizes that man is not really able to speak honestly about himself, but works as hard as he can to be honest, and, in the process, is better able to understand himself.
Again - just a theory - I am not inside of Bono's head, so I shouldn't claim to know who he is or what he's thinking.
Bono is also a bit of a philosopher, and his philosophy is (duh) influenced by his Christianity. Themes that he strongly believe in... love, especially... end up over and over again in his lyrics, in both positive and pragmatic ways (One, anyone?).
Just my $0.02.