Church that is to soar above all (7)
I believe the answer is:
chiefly
'above all' is the definition.
(I've seen this before)
'church that is to soar' is the wordplay.
'church' becomes 'ch' (common abbreviation).
'that is' becomes 'ie' (short for Latin 'id est', 'that is').
'to soar' becomes 'fly' (I've seen this in another clue).
'ch'+'ie'+'fly'='CHIEFLY'
(Other definitions for chiefly that I've seen before include "Mainly, principally" , "For the most part" , "In the main" .)