春は花 夏ほととぎす 秋は月 冬雪さえて すずしかりけり - Dōgen

As I study both the exoteric and the esoteric schools of Buddhism, they maintain that human beings are endowed with Dharma-nature by birth. If this is the case, why did the Buddhas of all ages — undoubtedly in possession of enlightenment — find it necessary to seek enlightenment and engage in spiritual practice?

It is only due to a lack of heart for the Way and a lack of skill in handling their daily conduct that people become vainly tied to fame and gain.

Firewood becomes ash, and it does not become firewood again.