For it is historically improbable that, after Easter, Jesus’ disciples carried on a mission to ’the lost sheep of the house of Israel’ (Mt. 10.6; 15.24) if Jesus himself never thought Israel was lost.
Dale C. Allison Jr., Jesus and the Covenant: A Response to E P Sanders, JSNT 9.57 (1987), p.74.
Allison here eloquently puts to rest Sanders' suggestion that Jesus was a covenantal nomist (eg Jesus and Judaism, p.336). The entire Christian movement is difficult to reconcile with a Jesus who accepted covenantal nomism (John the Baptist seems to have been considered as a forerunner in this regard--Matt.3.9 is a flat rejection of covenantal nomism, as Allison points out).