Interesting subject. We know that Christianity has shaped the band members and those ideas certainly enter into the lyrics. As noted in this thread, Bono is an affinity to the Psalms and even wrote the forward for a the Pocket Canon Series (1999). Bono starts be saying:
“Explaining belief has always been difficult. How do you explain a love and logic at the heart of the universe when the world is so out of whack? How about the poetic versus the actual truth found in the scriptures? <<skip>> Explaining faith is impossible…Vision over visibility…Instinct over intellect…A songwriter plays a chord with the faith that he will hear the next on in his head.”
I also appreciate the Psalms in the Hebrew Scriptures (along with the gift of the Prophets). What is striking about the Psalms are the large percentage that are Psalms of Lament. Bono certainly recognizes this and it bleeds into the songs. To me, many of the most spiritual U2 songs are the songs of lament, such as ‘Wake Up Deadman,” “If God will Send His Angels” and “Peace on Earth,” among many others. The Psalms let us know that it is ok to be angry at God.
Heaven on Earth, we need it now, I'm sick of all of this hanging around, Sick of sorrow, sick of the pain, I'm sick of hearing again and again, That there's gonna be peace on Earth
God's got his phone off the hook, babe, Would he even pick up if he could, It's been a while since we saw that child, Hanging 'round this neighborhood, See his mother dealing in a doorway, See Father Christmas with a begging bowl, Jesus' sister's eyes are a blister, The high street never looked so low
Jesus, were you just around the corner, Did you think to try and warn her, Or are you working on something new, Is there an order in all of this disorder, Is it like a tape recorder, Can we rewind it just once more