Endeavoured to be good person, motivated without leader (7)
I believe the answer is:
striven
'endeavoured' is the definition.
('strive' can be a synonym of 'endeavour')
'good person motivated without leader' is the wordplay.
'good person' becomes 'st' (saint).
'motivated' becomes 'driven' ('driven' can be similar in meaning to 'motivated').
'without leader' means to remove the first letter.
'driven' with its initial letter taken off is 'riven'.
'st'+'riven'='STRIVEN'
'to be' is the link.
(Other definitions for striven that I've seen before include "sought" , "Fought" , "Struggled" , "(Has) made great efforts" , "Battled" .)