Here is an essay I’ve written about immortality. I am aware that God is not a buddhist concept, but I believe you will find many aspects of this essay that are strikingly similar to concepts in buddhism. Either link below is fine, they are both the same content.
https://yourconstruct2.blogspot.com/
or
This is eteranlism, not buddhism.
Let go of Birth and Death. Let go of attachment to the body living forever and all the fear that impossibility causes. Then you will see the deathless. Which is also the endless. Because it is beginningless.