In the November 2006 issue of Shambhala Sun, Diana Mukpo, the widow of Chogyam Trungpa, is quoted as saying in her new book, "Ultimately I think that this is the essence of Buddhist teachings: they are about how to live our lives, intimately, moment to moment."
This is what truly separates Buddhism from most other religions. It's also the reason why many people claim Buddhism is not a religion but a philosophy. We don't focus on the philosophical quagmire of gods, spiritual cosmology, and the "afterlife." We work with what we have at our disposal, our minds, with the goal of holding mindfulness at every point of our waking existence and acting out of complete, total, pure compassion. This isn't to say that Buddhism is without said philosophical claptrap. Great sages, including the Buddha himself, have coherently expressed these ideas to bring a "philosophical wholeness" to the religion. However, the Buddha himself taught that such musings were unfruitful. While they might be fun (I certainly enjoy a good philosophical discussion!) and educational, such intellectual exercise cannot bring us peace, bring us mindfulness, or lead us to compassionate action. Only training of the mind can bring out such skillful means.
As Diana Mukpo expressed, the essence of Buddhism is the observation that events will happen to us, some pleasant, some unpleasant, and the only thing of which we can be sure is our response in the present moment. The past has ended--while we can, and should, use it for educational purposes, it cannot help us in the immediate moment. The future is just our worried or egotistical projection of what might happen--again, while it can be used for educational purposes, it can do nothing for the "here and now." The Buddha, before his Awakening, had faith that he could achieve perfect peace, perfect compassion, perfect wisdom, through training his mind. And he did achieve perfect peace, perfect compassion, perfect wisdom, while resulted in the ultimate happiness. So that we could do the same thing he did, the Buddha taught us "how to live our lives, intimately, moment to moment."