One has arguments against religious pictures (5)
I believe the answer is:
icons
'religious pictures' is the definition.
(I've seen this before)
'one has arguments against' is the wordplay.
'one' becomes 'i' (Roman numeral).
'has' says to put letters next to each other.
'arguments against' becomes 'cons' (I've seen this before).
'i'+'cons'='ICONS'
(Other definitions for icons that I've seen before include "Screen symbols on 4 across" , "Religious or computer images" , "Devotional paintings" , "Graphic symbols on computer screens" , "Images, religious perhaps" .)