If we give Qoheleth a serious hearing... we come to an entirely different conclusion: recognizing that my life is subject to vanity means that in the final analysis I cannot place myself in the center; not in the center of the world, not in the center of my circle of relationships, not in the center of history, action, or culture. We need to reflect on the importance of this shift of perspective. It does not amount merely to a rejection of egoism and egotism.... Such a shift also implies rejecting the belief predominant in the West that once we have asserted our culture and our economic concepts as the only valid ones, we can destroy other cultures and economic systems. Remember your culture and political system are vanity! And then listen to others and respect them! (p. 115 of Reason for Being)
My wife did a project recently over Ecclesiastes analyzing it from an integrative perspective of theology and psychology. I became very interested in it after reading her work. This book of Ecclesiastes helps us to look at the vanity (I would translate it "absurdity") of our own self and our own culture and world. How absurd that we place so much trust in ourselves, our way of life, our way of thinking, etc. Instead, we must give up this way of power and embrace the weakness of the cross.