Speedily - Suddenly, unexpectedly. He will surely vindicate them, and that at a time, perhaps, when they were nearly ready to give over and to sink into despair. This may refer to the deliverance of the disciples from their approaching trials and persecutions among the Jews; or, in general, to the fact that God will interpose and aid his people.
Nevertheless - But. Notwithstanding this. Though this is true that God will avenge his elect, yet will he find his elect “faithful?” The danger is not that “God” will be unfaithful - he will surely be true to his promises; but the danger is that his elect - his afflicted people - will be discouraged; will not persevere in prayer; will not continue to have confidence in him; and will, under heavy trials, sink into despondency. The sole meaning of this phrase, therefore, is, that “there is more danger that his people would grow weary, than that God would be found unfaithful and fail to avenge his elect.” For this cause Christ spoke the parable, and by the “design” of the parable this passage is to be interpreted.
Son of man cometh - This probably refers to the approaching destruction of Jerusalem - the coming of the Messiah, by his mighty power, to abolish the ancient dispensation and to set up the new.
Faith - The word “faith” is sometimes taken to denote the “whole” of religion, and it has been understood in this sense here; but there is a close connection in what Christ says, and it should be understood as referring to what he said before. The truth that he had been teaching was, that God would deliver his people from their calamities and save them, though he suffered them to be long tried. He asks them here whether, when he came, he should find “this faith,” or a belief of “this truth,” among his followers? Would they be found persevering in prayer, and “believing” that God would yet avenge them; or would they cease to pray “always, and faint?” This is not to be understood, therefore, as affirming that when Christ comes to judgment there will be few Christians on the earth, and that the world will be overrun with wickedness. That “may be” true, but it is not the truth taught here.
The earth - The land referring particularly to the land of Judea. The discussion had particular reference to their trials and persecutions in that land. This question implies that “in” those trials many professed disciples might faint and turn back, and many of his “real” followers almost lose sight of this great truth, and begin to inquire whether God would interpose to save them. The same question may be asked respecting any other remarkable visitation of the Son of God in affliction. When tried and persecuted, do “we” believe that God will avenge us? Do “we” pray always and not faint? Have “we” faith to believe that, though clouds and darkness are round about him, yet righteousness and judgment are the habitation of his throne? And when storms of persecution assail us, can “we” go to God and confidently commit our cause to him, and believe that he will bring forth our righteousness as the light, and our judgment as the noon-day?