I came across this Taoist quote on mortality:
“Immortality does not beget wisdom.
Only mortality begets maturity.”
– 365 Tao: Daily Meditations by Deng Ming-Dao
I scrolled through the Vatican sayings to find a few that seemed akin to the quote:
VS10. Remember that you are mortal, and have a limited time to live, and have devoted yourself to discussions on Nature for all time and eternity, and have seen “things that are now and are to come and have been."
VS14. We are born once and cannot be born twice, but for all time must be no more. But you, who are not master of tomorrow, postpone your happiness. Life is wasted in procrastination, and each one of us dies while occupied.
VS22. Unlimited time and limited time afford an equal amount of pleasure, if we measure the limits of that pleasure by reason.
VS78. The noble soul occupies itself with wisdom and friendship; of these, the one is a mortal good, the other immortal.
And this from the Letter to Menoceus:
“Become accustomed to the belief that death is nothing to us. For all good and evil consists in sensation, but death is deprivation of sensation. And therefore a right understanding that death is nothing to us makes the mortality of life enjoyable, not because it adds to it an infinite span of time, but because it takes away the craving for immortality.”
[Taoism is variable, with both naturalist schools (e.g. Lao Tzu and Chuang Tzu) and supernaturalist schools; the philosophical and the religious.]