Friendly expert going round church with unusual bliss (10)
I believe the answer is:
accessible
'friendly' is the definition.
(synonyms)
'expert going round church with unusual bliss' is the wordplay.
'expert' becomes 'ace' (ace can informally mean very good).
'going round' is an insertion indicator (some letters go around others).
'church' becomes 'CE' (abbreviation for Church of England).
'with' means one lot of letters go next to another.
'unusual' indicates an anagram.
'bliss' anagrammed gives 'ssibl'.
'ce'+'ssibl'='cessibl'
'ace' enclosing 'cessibl' is 'ACCESSIBLE'.
(Other definitions for accessible that I've seen before include "Easy to talk to; approachable" , "able to be reached" , "Open to be got at" , "Approachable; easily understood" .)