The Master was depressed by failure, or He merely wished to test His adherents, to find out if they had strength enough to follow Him through thick and thin.

If only He could be entirely sure of that, then He would hasten like the lightnings of heaven to annihilate the enemy and glorify His own adherents.

If, as He Himself had said, faith was so strong that it could remove mountains, it would be quite easy for Him to show His power at the propitious moment.
This firm belief of Judas made the disciple Thomas remember the Master's actual words about faith: Whosoever says to the mountain, Depart, and cast yourself into the sea, and does not doubt but _believes_ that it happens, for him it will happen.

Mark, _for him_ it will happen.

Whether others who do not believe will see the mountain fall into the sea He did not say.
"Then, brother Thomas," said Bartholomew, "you think things that happen through faith happen only for him who believes.