"Don’t think that birth
becomes death. Birth is its own time with its own past
. Thus in the Teachings of Awake Reality, birth is known to be “unborn”. Death is its own time, with its own past and future. Thus death is realized as “deathlessness”. In birth there is only birth, in death there is only death. Thus, when birth comes realize birth. When death comes realize death. Do not avoid or desire either of them.
This birth and death is itself the life of Awake Awareness. If you struggle to escape it you will lose the life of Awake Awareness. Also if you try to grasp it you will lose the life of the Awakened One and all you will have is the husk. Only when you don’t crave for or despise birth and death will you enter Awake Awareness
Do not try to measure it with your mind or describe it in words. Just cast body and mind into the realm of Awake Awareness. In this, you are free from birth and death and, without effort or worry, you become Awake If you realize this, there are no obstacles in your mind.
This is simply becoming Awake. Refrain from unwholesome acts, do not grasp at birth and death, respect seniors and be kind to juniors, give up hope and fear, worry and grief. This is called Awake. Do not look elsewhere."
from Eihei Dogen zenji, Shobogenzo: Shoji, Birth and Death, translated by Yasuda Joshu Dainen and Anzan Hoshin, Progress Into the Ordinary, Great Matter Publications, 1986; used with permission