He came into His kingdom before that generation passed away. You're told that repeatedly in the Book.
Wrong. Late date theory is a house of cards when brought under scrutiny; to quote Robert Young:
"
It was written in Patmos about A.D.68, whither John had been banished by Domitius Nero,
as stated in the title of the Syriac version of the Book; and with this concurs the express statement of Irenaeus (A.D.175), who says it happened in the reign of Domitianou, ie., Domitius (Nero).
Sulpicius Severus, Orosius, &c., stupidly mistaking Domitianou for Domitianikos, supposed Irenaeus to refer to Domitian, A.D. 95, and most succeeding writers have fallen into the same blunder. The internal testimony is wholly in favor of the earlier date." (Concise Critical Comments on the Holy Bible, by Robert Young.”
In other words Young says it's a 'stupid mistake' by Sulpicius Severus and others that has resulted in
A DOMINO EFFECT of bad information concerning the dating of Revelation down through the centuries.
Also, there is compelling internal evidence within the book itself that much of it is concerned with the 70 AD destruction of Jerusalem:
And I saw another sign in heaven....and them that come off victorious from the beast... they sing
the song of Moses the servant of God....Rev 15.1-3
The song of Moses is being sang in heaven in the 15th chapter of Revelation, which is very significant when you consider that the song of Moses had only one purpose and time, and that was to 'testify before Israel as a witness against them' when they had utterly corrupted themselves and evil had befallen them in the 'latter days':
16 And Jehovah said unto Moses.....this people will rise up, and play
the harlot ...and break my covenant which I have made with them.
17 Then my anger shall be kindled against them
in that day.....and
many evils and troubles shall come upon them; so that they will say
in that day, Are not these evils come upon us because our God is not among us?
18 And I will surely hide my face in that day for all the evil which they shall have wrought.....
19 Now therefore
write ye this song for you...... that
this song may be a witness for me against the children of Israel.
21....when many evils and troubles are come upon them, that
this song shall testify before them as a witness.....
29 For I know that after my death
ye will utterly corrupt yourselves, and turn aside from the way which I have commanded you;
and evil will befall you in the latter days; because ye will do that which is evil in the sight of Jehovah, to provoke him to anger through the work of your hands.
30 And Moses spake in the ears of all the assembly of Israel the words of this song, until they were finished. Dt 31
The Song of Moses is quoted from by both Christ and the Apostles in reference to
'that evil generation' of Jews of their day in the gospels and the epistles.
And concerning the external evidence that the book was written prior to 70 AD, there is just as much or more that points to the earlier date:
http://www.eschatology.org/index.ph...-revelation-guest-article&catid=40&Itemid=211