Err again perhaps to get frankincense or myrrh? (5)
I believe the answer is:
resin
I believe this clue is a double definition.
'err again perhaps' is the first definition.
(re-sin, to sin again)
'frankincense or myrrh?' is the second definition.
(both are resins)
'to get' is the link.
(Other definitions for resin that I've seen before include "Sticky tree exudation" , "Substance obtained from sap of certain plants - transgress again" , "Myrrh, for instance" , "Fiddler's need" , "viscous material" .)