A very large portion of the Gospel of St Mark is to be found, with only very slight alterations, in St Luke. Not unfrequently the reason for the alteration is clear enough, and is due to the desire of the latter writer to express himself with greater clearness than St Mark had done, or else is the result of efforts to improve the style.
Style
St Luke was a very much better Greek scholar than was St Mark, for Greek was quite possibly his own mother tongue, and he writes it with a greater purity and literary skill than does any other of the New Testament authors. St Mark's style, on the other hand, is full of Hebraisms and awkward expressions. It is the style of a man who is writing a language with which he has indeed a considerable acquaintance, but over which he is very far from possessing a complete mastery. He thinks in Hebrew though he writes in Greek, and consequently is apt to be Hebraic, although the words and the grammatical construction are in themselves good enough Greek.
The Inference
These awkwardnesses of expression are for the most part removed by St Luke, and account for a large part of the alterations, but even after we have made the fullest allowances for this cause there remain a certain number of changes and differences, of omissions and additions, which cannot be accounted for in this way, and which suggest, if they do not actually prove, that it was not from a document in all respects identical with our present Gospel of St Mark that St Luke drew this portion of his information, but from one which very greatly resembled it, and was probably simply an earlier form of the existing Gospel. There is no necessity, however, for us to go at all deeply into this question, for it is one upon which scholars are not agreed, and in any case the document used by St Luke differed so little from our present Gospel of St Mark that we may be content in a mere sketch such as this to leave the matter without further investigation.