Robinson (now deceased) was an Anglican bishop who published books that ruffled conservative feathers. He decided as a joke to try to prove that all the gospels were written before 70 AD, an idea then regarded as ridiculous.
The result was "Redating the New Testament" which showed why early dating is more logical. The book has become famous. Fads in biblical scholarship have come and gone and their works gather dust in libraries. But Robinson's book continues to impact.
Robinson's main argument is that all the gospels must have been written before 70 AD when the temple in Jerusalem was burned to the ground. And it is very, very strange that the destruction isn't mentioned. Why? Because the gospels repeatedly state that Jesus predicted that "not one stone would remain on another" of the temple (Mark 13:2, Luke 21:5, and Matthew 24:1). So then why didn't the evangelists try to score points by pointing out the destruction?
And even stranger: Jesus predicted in Matthew 24 that "this generation shall not pass away" until they saw the temple pulled down. Then, sure enough, 40 years (40 years = one generation for the ancient Jews) to the day the temple fell. Again, if the gospels were written after the temple's destruction, why didn't anyone mention it?
The temple was destroyed during a short, brutal war between the Jews and the Romans. The war left one million Jews dead, their country in ruins, and the temple burned to the ground. Few people today can grasp how shattering that would be to the Jews, and how significant for Christians. The entire theocracy of the Jews was extinguished. Gone were the Sadduccees. Burned along with the temple were all records proving lineage, and thus, the priesthood was destroyed. Never again could there be a high priest. Or a sacrifice. There was no longer a legal outlet for purgation from sin for the Jews.
Historically, the war also marked a permanent breach between Jews and Christians. Henceforth, they were utterly separate. One reason may be because, as Eusebius says, the Christians refused to take part in the insurrection and stayed in Pella.
By the way, Robinson's argument is not new. He even quotes Torrey, who puts it quite succinctly: "It is perhaps conceivable that one evangelist writing after the year 70 might fail to allude to the destruction of the temple by the Roman armies...but that three or four should thus fail is quite incredible. On the contrary, what is shown is that all four gospels were written before the year 70."
All four gospels refer to the temple in the present tense, saying the temple "is" instead of "was". And then there is the temple tax issue. There was no reason for the gospel writers to insist that everyone pay the temple tax once the temple was destroyed.
In sum, Robinson argues that Matthew, Mark, Luke and Acts were all written before 65 AD. Some portions may have been written in proto-Matthew (Q) in the early 40s. He concluded John was written before 70 AD, as well as James and the Didache.
Anyone interested in this subject should read "Redating Matthew, Mark, and Luke" by John Wenham, who also supports early dates. Another book arguing for early dates is Jean Carmignac's "Birth of the Synoptic Gospels". Carmignac, a noted linguist and Dead Sea scroll scholar, insists he found linguistic and textual proof some of the gospels were written in Hebrew.