What is a negative way to describe a person who is overindulged with Earthly life?
Solution 1:
My first thought was Hedonist. Oxford (linked on the word) gives the definition as “A person who believes that the pursuit of pleasure is the most important thing in life; a pleasure-seeker”, which doesn’t include the implications of ignoring or neglecting things beyond pleasure, but is nevertheless generally perceived as negative.
Solution 2:
One option is: decadent.
One of Wiktionary's definitions is:
Luxuriously self-indulgent
which seems to cover the intended meaning well.