Jesus tells the high priest that he (the priest) would see his (jesus') return
- Mark 14:61-62
He told three disciples that they would (live to) see his return
- Matt 16;28
He told the disciples he would return before they had preached throughout Palestine
- Matt 10:23
The generation living at that time (circa 30 christian era) was to be still be alive when "all these things" took place
- Mark 13:3-30
Might be worth noting that current scientific opinion holds that the world has not yet ended.
However it has been shown that the generations of all the actors in the bible have long since passed. Hmmm.
Those who crucified him will see him return (2nd time) "with their own eyes"
- Revelation 1:7
Despite saying all these definite statements above, only seconds later he tells the disciples that no one - including himself (I thought he knew *everything*) - knew when the end would come
- Mark 13:32