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.
Causing suffering and death on other conscious beings makes you grow old and die. Refrain from causing suffering and death and you can make yourself immortal. And just to clarify, I do mean actual physical immortality where you live forever in the physical body that you inhabit; none of this immortal soul or immortal consciousness nonsense, I mean immortal physical body.
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.
One thing that was a sticking point in my mind were interpretations of words like attachment, suffering, I think I am coming to a better understanding when thinking more around the word acceptance.
I have PTSD from child abuse. And it's taken a long time for me to accept that I am not neurotypical. To let go of my expectations (attachments) of who I'm 'supposed' to be.
I was attached to being like everybody else. Now that I've accepted that I'm different, I can work with my PTSD with compassion.