death and immortality in poetry

Hi everyone, i'm writing an essay on the subject of Death and Immortality as depicted in selected poems. I'm gonna analyze four poets' works : John Donner"death be not proud"; Tennyson"crossing the bar"; william bryant " Thanatopsis" and Dickinson's "because i could not stop for death" "i heard a fly buzz when i died" "parting".

It's not difficult simply to analyze them individually. But i'm still thinking how am i gonna compare these works. What's the universality in the nature of death that we can observe in these poems. Can anyone help me? Any suggestion would be appreciated.

Thanks in advance!