Apostle meeting God? It's child's play (5,3)
I believe the answer is:
peter pan
'child's play' is the definition.
(play for children by JM Barrie)
'apostle meeting god?' is the wordplay.
I cannot quite understand how this works, but
'apostle' could be 'peter' (Peter is an example) and 'peter' is found within the answer.
'god?' could be 'pan' (Pan is an example) and 'pan' is found within the answer.
No letters remain.
This explanation may well be incorrect...
'it's' is the link.
(Other definitions for peter pan that I've seen before include "Pantomime hero" , "Ever-youthful boy" , "J M Barrie's boy who never grew up" , "Musical from Barrie play" , ",one with youthful persona, maybe" .)