Lacking principles -- must keep time for God, perhaps (8)
I believe the answer is:
immortal
'god perhaps' is the definition.
I can't tell whether this definition defines the answer.
'lacking principles must keep time' is the wordplay.
'lacking principles' becomes 'immoral' (I've seen this in another clue).
'must keep' means one lot of letters goes inside another.
'time' becomes 't' (abbreviation).
'immoral' enclosing 't' is 'IMMORTAL'.
'for' is the link.
Can you help me to learn more?
(Other definitions for immortal that I've seen before include "Moral Tim (anag.)" , "never to be forgotten" , "Great person" , "Never dying" , "Imperishable" .)