Faith said to be tied up (7)
I believe the answer is:
trussed
'be tied up' is the definition.
(I've seen this before)
'faith said' is the wordplay.
'faith' becomes 'trust' ('trust' can be a synonym of 'faith').
'said' shows a homophone (sound like).
'trust' is a homophone of 'TRUSSED'.
'to' is the link.
(Other definitions for trussed that I've seen before include "Bundled up" , "Bound up tightly" , "Dusters (anag) - bound" , "Secured" , "Tied up" .)