Discover more about one of the four keys to the Gate of Heaven: As it turns out, Buddha had quite a lot to say on the subject of gratitude, including citing it as one of the four keys to the Gate of Heaven. Why is this? Perhaps the sheer simplicity of gratefulness is a large part of this, as it is available to all of us at any time. Even in the midst of over-busyness, stress, and chaos, we can find plenty to be glad about, and The Buddha's Guide to Gratitude will start your journey towards Zen and gratefulness.