Obama spoke at length also of religion, both as a catalyst of conflict and a corrective:

As the world grows smaller, you might think it would be easier for human beings to recognize how similar we are; to understand that we're all basically seeking the same things; that we all hope for the chance to live out our lives with some measure of happiness and fulfillment for ourselves and our families.

And yet somehow, given the dizzying pace of globalization, the cultural leveling of modernity, it perhaps comes as no surprise that people fear the loss of what they cherish in their particular identities -- their race, their tribe, and perhaps most powerfully their religion. In some places, this fear has led to conflict. At times, it even feels like we're moving backwards. We see it in the Middle East, as the conflict between Arabs and Jews seems to harden. We see it in nations that are torn asunder by tribal lines.

And most dangerously, we see it in the way that religion is used to justify the murder of innocents by those who have distorted and defiled the great religion of Islam, and who attacked my country from Afghanistan. These extremists are not the first to kill in the name of God; the cruelties of the Crusades are amply recorded. But they remind us that no Holy War can ever be a just war. For if you truly believe that you are carrying out divine will, then there is no need for restraint -- no need to spare the pregnant mother, or the medic, or the Red Cross worker, or even a person of one's own faith. Such a warped view of religion is not just incompatible with the concept of peace, but I believe it's incompatible with the very purpose of faith -- for the one rule that lies at the heart of every major religion is that we do unto others as we would have them do unto us.

Adhering to this law of love has always been the core struggle of human nature. For we are fallible. We make mistakes, and fall victim to the temptations of pride, and power, and sometimes evil. Even those of us with the best of intentions will at times fail to right the wrongs before us.

But we do not have to think that human nature is perfect for us to still believe that the human condition can be perfected. We do not have to live in an idealized world to still reach for those ideals that will make it a better place. The non-violence practiced by men like Gandhi and King may not have been practical or possible in every circumstance, but the love that they preached -- their fundamental faith in human progress -- that must always be the North Star that guides us on our journey.

For if we lose that faith -- if we dismiss it as silly or naïve; if we divorce it from the decisions that we make on issues of war and peace -- then we lose what's best about humanity. We lose our sense of possibility. We lose our moral compass.