“Luke and John written shortly after 70 A.D.”
For Luke, this is an impossibility, because Paul quotes Luke’s Gospel according to the Greek he employed, and Paul likely perished sometime in the early 60s.
1Ti_5:18 For the scripture saith, Thou shalt not muzzle the ox that treadeth out the corn. And, The labourer is worthy of his reward.
Luk_10:7 And in the same house remain, eating and drinking such things as they give: for the labourer is worthy of his hire. Go not from house to house.
Notice also that it is called “scripture.”
The Book of Acts also must have been written before 70AD, because it contains none of the events that occurred 60+ or the destruction of the Jewish Temple, which would have been considered by the Christian church as worthwhile to note not just because of the 3 or so million people who died, but because it was the fulfillment of prophecy.
Did you ever hear of journaling?
Of course Luke wrote some of it while he was with Paul.