Very interesting -- a mix of various iconographical types. I found a somewhat similar jeton on an Italian site La Moneta: http://www.lamoneta.it/topic/49016-moneta-non-identificata/
(later edit: I had to sign in with Google to be allowed access to the images!)
The abbreviated text on the reverse is taken from an adaptation of Philippians 2.8: Christus factus est pro nobis obediens usque ad mortem, mortem autem crucis, "Christ was made [by God] for us, obedient even unto death, even death upon the cross." This phrase was an integral part of the medieval mass.
Feuardent lists a jeton with a very similar reverse as #4012 (listed under "Eglises de Paris" under a subheading "Jetons with mottoes and figures of the gros tournois or denier tournois, St Louis type") (The obverse has designs like a gros tournois). He states that he's really not at all sure that this subheading group really belongs under "Eglises de Paris," that some may have been produced outside of France, and that they may have been produced as amulets for fishermen, who were known to prefer medalets of this type.