10 This, then, He is about to show us; this He showed to His disciples, who saw Him in the flesh. What is this? “As the Father raises the dead, and quickens them, so also the Son quickens whom He will.” Is it that the Father some, the Son others? Surely all things were made by Him. What do we say, my brethren? Christ raised Lazarus; what dead man did the Father raise, that Christ might see how to raise Lazarus? When Christ raised Lazarus, did not the Father raise him?
Or was it the doing of the Son alone, without the Father? Read ye the passage itself, and see that He invokes the Father that Lazarus may rise again. As a man, He calls on the Father; as God, He does with the Father. Therefore also Lazarus, who rose again, was raised both by the Father and by the Son, in the gift and grace of the Holy Spirit; and that wonderful work the Trinity performed. Let us not, therefore, understand this, “As the Father raises the dead, and quickens them, so also the Son quickens whom He will,” in such wise as to suppose that some are raised and quickened by the Father, others by the Son; but that the Son raises and quickens the very same whom the Father raises and quickens; because “all things were made by Him, and without Him was nothing made.”
And to show that He has, though given by the Father, equal power, therefore He says, “So also the Son quickens whom He will,” that He might therein show His will; and lest any should say, “The Father raises the dead by the Son, but the Father as being powerful, and as having power, the Son as by another's power, as a servant does something, as an angel,” He indicated His power when He says, “So also the Son quickens whom He will.” It is not so that the Father wills other than the Son; but as the Father and the Son have one substance, so also one will.
Source: Tractates on the Gospel of John (New Advent)