Dunno if you read, a couple of months ago, of some two-millennia-old Biblical fragments recently discovered in caves in the Judean deaert. One of them (Zechariah 8:16-17) was ... except for the Tetragrammaton ... written in Greek.
Greek was the lingua franca of the Mediterranean world. Rome was the lergest Greek-speaking city in that world. Non-Greek languages survived in circumstances of bilinguality. Think Palestine ... think Wales ...
But we know that Christ spoke Aramaic. This raises an interesting question. The Gospels of Matthew, Mark, and Luke contain long passages which are more or less verbally identical.
IF YOUR ARE SPEED-READING THIS, YOU MIGHT AS WELL SAVE YOURSELF TIME BY GIVING IT UP NOW.
Now: if you ask three people to translate a single text into a different language, it is highly improbable that their three renderings will be verbally identical, even reproducing the same word-order. In a classroom, you will work out whose work was passed around and then plagiarised by the other "students". Time was when, at this point, the cane came out of the cupboard. Not that I ever used one. I relied on Mental Cruelty.
So, clearly, one needs an answer to the problem of the Three Synoptic Gospels. Who did the original translation of the words of the Lord from Aramaic into Greek? Mark is shorter and cruder, so he is clearly first. The other two borrowed from him. What about passages in Matthew and Luke which are not borrowed from Mark? It stands to reason that they were taken from a now-lost work which wiser men than me (or you) have called 'Q'.
Bingo! You have solved "the Synoptic Problem".
But do we know that Christ spoke Aramaic? Of course we do. Mark records him as using the Aramaic Talitha Coum(i) when raising Jairus' daughter. And Abba and Ephphatha. QED.
But why does Mark only record a few odd Aramaic words? Modern Scientific Commentators go shifty at this point. Do these words safely record Christ as an Aramaic speaker ... or do they neatly record some rare occasions when a habitual Greek-speaker spoke Aramaic instead?
In conditions of bilinguality, the 'old' language ... Welsh or Aramaic ... may still be used round the hearth, in families, by women and children. The chaps will use the big, cosmopolitan language ... English, let us say, or Greek. But when turning to babies, young girls, the handicapped, they might well use the 'informal' local language. I have heard educated speakers of 'Establishment' English automatically using the Glottal Stop when they address children or minorities which they (perhaps unconsciously) despise.
I have a fair bit more to say on all this. But first let me dispose of the 'Priority of Mark' ...shorter, cruder, therefore clearly first of the Gospels to have been written.
A great Oxford papyrologist called Peter Parsons once gave a paper, not on any biblical subject, but on Classical Literature. Particularly the chronology of the plays of Aeschylus. Recent papyrological discoveries had revealed that the Supplices was quite late in the playwrite's oeuvre. But it had always been assumed that it was among his first plays ... because of its 'primitive' structure etc, etc..
Parsons adduced other examples of the dangers of facile a priori assumptions.
One of the problems about Modern Scientific Biblical Scholarship is that those involved in it are often much too proud to take any notice of those outside their own narrow, precious, speciality. Particularly of us Classicists! More on this later.
If Christ habitually spoke Greek, then the 'Synoptic Problem' disappears into thin air. Massive numbers of 'learned' books and articles are ... Crass. No; we do not need another imaginative reconstruction of 'Q'.
And the 'new' Judean manuscript makes clear (what we well knew already) that Christ would not have been the only faithful Jew to speak Greek. Indeed, consider the varied names recorded of His disciples. PHILIPPOS is not only a Greek name; it is redolent of the Macedonian North Greek culture which became part of the common hellenic currency of the regions which had been conquered by Alexander the Great and ruled by his 'Successors'. 'ANDREAS is Greek for ... no; I will leave to you the fun of speculating. You might enjoy including in your speculations the names of the hellenised Chief Priests mentioned in the Books of the Maccabees.