Ruru-sama
This is Kawaguchi Hidetoshi. This is my humble answer to the question.
This time, I would like to speculate that it is a question that made you feel even more familiar with the reality of “death” when your father passed away. I sincerely pray for your father's peace of mind.
“Death” comes to everyone without exception, but everyone is afraid of “death”... Of course, in terms of Buddhism, I know that it can be overcome by firmly understanding the essence of “reincarnation” in Mizukami's answer.
As for “life and death,” “death” is not an “end.” Also, “life” is not a “beginning.” It's called “no beginning and end.” Kobo Daishi describes this in “Born, Born, Born, Born, Dark at the Beginning of Life, Dying, Dying, Dying, and Meditating at the End of Death” and “Treasured Treasures.”
Regarding “unfounded and endless,” for example, it is also related to the eight values of “immortal immortal, immutable, impermanent, impermanent, and impermanent” in Ryuju Daishi's “Middle Theory,” but although these are important ways of thinking to suggest “infatuation theory” and “sky,” this understanding is extremely difficult.
In terms of the famous phrase “those who leave don't leave,” when explaining “immortality,” it means “those who die don't die.” This also means “you won't die” in response from Mr. Tange.
Also, there are many questions related to “the meaning of life” as shown below.
http://hasunoha.jp/questions?tag=生きる意味
Among these, in the question “The meaning of living” http://hasunoha.jp/questions/93, I answered “If there is a meaning to live, there is no point in living” with a slightly riddle title.
What I can say here is that from the ultimate truth level, it is “immortality” in terms of life and death, and “there is no meaning” in terms of “meaning,” but on a secular level, “there is life and death” and “there is meaning.”
Anyway, it's difficult. More than anything else, I think the most important thing is not to think too much about things you don't understand or can't get an answer to, and live better, the reality that is right in front of you “now,” to the fullest.
Kawaguchi Hidetoshi Gassho