John 5:21

For as the Father … giveth life, so also the Son giveth life to whom he will; where these words, to give life to whom he will, shew the power of the Son and of the Father to be equal. (Witham) — Our Saviour here mentions the greater works he spoke of in the preceding verse; for it is much more wonderful that the dead should rise, than that the sick should recover their health. We are not to understand these words, as if they meant some were raised to life by the Father, and others by the Son; but that the Father raises those whom the Son raises. And lest any one should understand this, that the Father makes use of the Son as his minister, through whose means he raises the dead, he immediately adds, &c. (St. Augustine, Tract. xxi. in Joan.) — We see the lovers of this temporal and perishable life, labour to the utmost of their power, I will not say to avoid death, but merely to prolong their frail existence. If, therefore, men labour with so much solicitude, if they strain every nerve to prolong their lives but for a few years; how foolish and blind to their interest must those be, who live in such a manner as to be deprived of the light of eternal day! (St. Augustine, De verb. Dni. Serm. 64.)

Verses 17-23 The Divine power of the miracle proved Jesus to be the Son of God, and he declared that he worked with, and like unto his Father, as he saw good. These ancient enemies of Christ understood him, and became more violent, charging him not only with sabbath-breaking, but blasphemy, in calling God his own Father, and making himself equal with God. But all things now, and at the final judgment, are committed to the Son, purposely that all men might honour the Son, as they honour the Father; and every one who does not thus honour the Son, whatever he may think or pretend, does not honour the Father who sent him.

(1.) Observe what is here said concerning the Mediator's power to raise the dead and give life. See [1.] His authority to do it (v. 21): As the Father raiseth up the dead, so the Son quickeneth whom he will. First, It is God's prerogative to raise the dead, and give life, even his who first breathed into man the breath of life, and so made him a living soul; see Deut 32 30; 1 Sam 2 6; Ps 68 20; Rom 4 17. This God had done by the prophets Elijah and Elisha, and it was a confirmation of their mission. A resurrection from the dead never lay in the common road of nature, nor ever fell within the thought of those that studied only the compass of nature's power, one of whose received axioms was point blank against it: A privatione ad habitum non datur regressus—Existence, when once extinguished, cannot be rekindled. It was therefore ridiculed at Athens as an absurd thing, Acts 17 32. It is purely the work of a divine power, and the knowledge of it purely by divine revelation. This the Jews would own. Secondly, The Mediator is invested with this prerogative: He quickens whom he will; raises to life whom he pleases, and when he pleases. He does not enliven things by natural necessity, as the sun does, whose beams revive of course; but he acts as a free agent, has the dispensing of his power in his own hand, and is never either constrained, or restrained, in the use of it. As he has the power, so he has the wisdom and sovereignty, of a God; has the key of the grave and of death (Rev 1 18), not as a servant, to open and shut as he is bidden, for he has it as the key of David, which he is master of, Rev 3 7. An absolute prince is described by this (Dan 5 19): Whom he would he slew or kept alive; it is true of Christ without hyperbole.