I lurk in shadow and all around,
I am always near,
I come after one and all,
Gender, age, nationality, and religious beliefs matter not to me,
I come in various forms,
You can delay me, but you can't escape me,
Time is on my side,
I can be quick or I can be slow,
I can be painful or I can be painless,
I am immortal,
I am always on time.
Who am I?