The last few paragraphs are confounding. Does the Pope truly believe that the muslims and the Christians share the same God? If he does, then he is sadly wrong. Until the truth is told about that, then the quest for peace will go unanswered.
The mentions of monotheism apparently sailed over your head.
I think he is referring to monotheism in the sense of the God of Abraham. In a sense, neither Muslims nor Jews believe in the Trinitarian God.
What the Pope means by Monotheism is, basically, what Christians mean by it—one God, three Persons, the Trinity.
He mentions Islam at the end, but does not address the issue of whether Allah is the one God of the Bible. He only prays that Christians and Muslims may live together in peace. That’s not likely, given what Muslims are, but there’s nothing wrong in hoping for a miraculous solution to the problems of the Middle East.