Indeed, one must always be ready to use gospel when it serves one's purposes, but when it does not, then we must turn to tradition to win our point.  Now we all know that using scripture when it suits us, and dismissing it as mere sola scriputura when it does not suit us is not the same as scoffing, so no risk imparts to those who merely use scripture as a tool to further their particular views.  Picking verses to serve our ends, or to condemn others while claiming to not be passing judgment is a tradition strongly rooted in the depths of time.  I believe Augustine may have expounded on this point, or maybe it was someone more recent.