St Luke set to work in his own way with an eye to exact information and orderly narrative (1:3), but respect for his sources, together with his method of juxtaposing them, meant that even Luke was not in a position to arrange his traditional material in a more chronological way than Matthew or Mark. His plan follows Mark’s outline though some episodes are displaced (3:19-20; 4:16-30; 5:1-11; 6:12-19; 22:31-34, etc.). This he did sometimes in the interests of clarity and logical sequence, sometimes under the influence of other streams of tradition including, it should be noted, a tradition traceable to the fourth gospel.
Other episodes are omitted altogether for various reasons: they were not interesting for Luke’s non-Jewish readers (Mk 9:11-13), or they were already to be found in the Supplementary Collection (Mk 12:28-34); cf. Lk 10:25-28), or above all (as in the case of Luke’s great omission of Mk 6:45-8:26) because it was not in Luke’s copy of Mark or because, if it was there, Luke regarded it as unnecessarily repetitive. Luke’s most obvious difference from Mark is his great intercalation (cf. 9:51-18:14) which, as has been seen, combines Logia or Sayings from some Collection with information he had found out for himself. This central section uses a journey to Jerusalem for its framework (cf. the reiterated indications, elaborating the datum of Mk 10:1, in Lk 9:51; 13:22, 17:11) . But it is not a reminiscence of actual journeys; it is rather a device by which Luke is able to bring out one of his chief theological notions: namely that the Holy City is the predestined stage for the drama of salvation (9:31; 13:33; 18:31; 19:11). Because it is from Jerusalem that the evangelisation of the world must begin (24:47; Ac 1:8), his gospel had to start there (1:5f) and there he will have to bring it to a close (24:52f) – the post-resurrection apparitions and conversations recorded by Luke do not take place in Galilee (cf. 24:13-51) and cf. 24:6 with Mk 16:7; Mt 28:7, 16-20).
Comparing Luke and his two sources, a. Mark, the best known, and b. the sources behind the Matthew passages which are paralleled in Luke, it becomes clear that Luke was a craftsman whose concentration never slackened.
(Jerusalem Bible, Darton, Longman & Todd Ltd, 1966)
(to be completed)