Middle English religious vocabulary is radically different from that of the previous period: while Old English is characterised more by lexical pattern replication of Latin (and Greek) etyma, Middle English is the period of matter replication. Due to the intake of new French religious words, English lexemes and also whole word families undergo semantic transformation and lexical replacement. Other terms, however, survive from the Old English period into the present day, resisting contact-induced pressure. This study shows that the survival of old lexemes into Middle English is largely determined by the extent of their diffusion and frequency of occurrence before the Norman Conquest. It is postulated that two kinds of inherited Old English lexis should be distinguished in the Middle English period: (i) established terms that had belonged to the West Saxon standard and were still preserved in general use by the lower regular clergy, parish priests and the faithful at large, and (ii) terms of limited currency that had failed to spread outside local communities with strong ties and survived for a short time after the Conquest in smaller religious foundations. The innovation and spread of new francophone religious lexis was conditioned by the new preaching practices that began to develop in Europe in the wake of the Fourth Lateran Council and the emergence of mendicant orders. Preachers of the new type were the multilingual innovators who generated new lexis in English and at the same time were instrumental in its diffusion, serving as weak ties between the various levels of the medieval society. Urban middle classes, on the other hand, were the most likely English-speaking early adopters of new norms.