en_tn_lite_do_not_use/1co/15/31.md

I die daily

Paul refers to denying the desires to sin.

if I fought with beasts at Ephesus

Possible meaning are 1) Paul was speaking figuratively about his arguments with learned pagans or 2) If he was to be put into the arena to fight against dangerous animals.

Let us eat and drink, for tomorrow we die

Paul concludes that if there is no further life after death, it is better for us to enjoy this life as we can for tomorrow our life will end without any further hope.