170:4.15 Although Jesus referred one phase of the kingdom to the future and did, on numerous occasions, intimate that such an event might appear as a part of a world crisis; and though he did likewise most certainly, on several occasions, definitely promise sometime to return to Urantia, it should be recorded that he never positively linked these two ideas together.
He promised a new revelation of the kingdom on earth and at some future time; he also promised sometime to come back to this world in person; but he did not say that these two events were synonymous. From all we know these promises may, or may not, refer to the same event.
His apostles and disciples most certainly linked these two teachings together. When the kingdom failed to materialize as they had expected, recalling the Master’s teaching concerning a future kingdom and remembering his promise to come again, they jumped to the conclusion that these promises referred to an identical event; and therefore they lived in hope of his immediate second coming to establish the kingdom in its fullness and with power and glory. And so have successive believing generations lived on earth entertaining the same inspiring but disappointing hope.