Odd! Is He with them with them once and not with them in another. Makes me wonder if they themselves did not pursue this because of the iron chariots instead.
Great and terrible things shall come. He could have said be strong or be prayerful etc... but He says to be patient. It is not that these other things are not each important, it is that they all come as a result of patience. Therefore posses your soul in patients.
Some of Israel (not all) was regathered at the end of the seventy years. The Temple was rebuilt and put back into service but, the hearts of Israel barely changed. They awaited an even more horrific judgment that Jesus himself would prophecy. In Jesus Christ a new spirit is given and hearts were changed but, Israel not regathered awaiting a final gathering yet to come in the end of the age of Gentiles. We see that every word of this prophecy is accurate, the time-line however not as direct as we might read.