(20) At that day ye shall know--i.e., the day of the gift of the Comforter, in whom Christ shall come to them. In the first reference the Day of Pentecost is meant, but the words hold good of every spiritual quickening, and will hold good of the final coming in the last day. The pronoun "ye" is emphatic--"Ye shall know for yourselves."

That I am in my Father, and ye in me, and I in you.--Comp. Note on John 10:38. The result of this spiritual illumination would be that they should of themselves know the immanence of the Son in the Father, and their own union with the Father through Him. They ask now (John 14:8) for a manifestation of the Father. The Spirit should so bring the life of Christ to their hearts that they would read in it the manifestation of the Father, and feel that in and through that life their own spirit has communion with God. The Spirit would witness with their spirit that they were the children of God. They would seek no longer for a Theophany from without, but in the depth of their inmost lives would cry, "Abba, Father."

Verse 20. - In that day of glorious re-communion with you, begun in the Resurrection-surprises, which will aid your faith and triumphantly establish the mysteries and marvels of Pentecost, you shall know what you now most imperfectly apprehend by faith, that I am in my Father, as One lifted up into God, and that I act entirely with and for and as my Father, fulfilling all that I have told you of my personal relationship with him; and then, he adds, you shall know that as I am in my Father, you (are) in me, living in and by my power, and continuously drawing life from me; and what is still more, I in you; i.e. as the Father has acted in and through my will, and I have spoken his words and done his works, so I will energize in you. Your "greater works" will prove my "greater power." Your own consciousness of my presence, and of continuous communion with me, will reveal to you, as you never knew before, that I am in my Father, and also that I am in you. So the apparent paradox presents itself, that in order to know the Father, to see the Father, we must commune with the humanity of Jesus; but in order to realize and come into contact with that humanity, we have to grasp that it is lifted up into God. Because he is in the Father he is able to be with and in us.

14:18-24 Christ promises that he would continue his care of his disciples. I will not leave you orphans, or fatherless, for though I leave you, yet I leave you this comfort, I will come to you. I will come speedily to you at my resurrection. I will come daily to you in my Spirit; in the tokens of his love, and visits of his grace. I will come certainly at the end of time. Those only that see Christ with an eye of faith, shall see him for ever: the world sees him no more till his second coming; but his disciples have communion with him in his absence. These mysteries will be fully known in heaven. It is a further act of grace, that they should know it, and have the comfort of it. Having Christ's commands, we must keep them. And having them in our heads, we must keep them in our hearts and lives. The surest evidence of our love to Christ is, obedience to the laws of Christ. There are spiritual tokens of Christ and his love given to all believers. Where sincere love to Christ is in the heart, there will be obedience. Love will be a commanding, constraining principle; and where love is, duty follows from a principle of gratitude. God will not only love obedient believers, but he will take pleasure in loving them, will rest in love to them. He will be with them as his home. These privileges are confined to those whose faith worketh by love, and whose love to Jesus leads them to keep his commandments. Such are partakers of the Holy Spirit's new-creating grace.At that day ye shall know,.... The things they should know, or the objects of knowledge are,

that I am in my Father; in his bosom, in union with him, partaker of the same nature, perfections, and glory with him, and equal to him:

and you in me: that they were in union with him as the branches in the vine, and as the members are in the head, and how they were loved in him, chosen in him, righteous in him, risen with him, and made to sit together in heavenly places in him:

and I in you; formed in their hearts, living in them, dwelling in them, as in his temples, and filling them with grace and glory. The knowledge of these things promised, designs a more clear and distinct knowledge of them; something of them was known already, but not so perfectly as should be hereafter; and this does not suppose that these unions between the Father and Christ, and between Christ and his people, shall then begin to be; for as the union between the Father and the Son is as eternal as themselves; so the union between Christ and his people, as he is the head and representative of them, is as early as his investiture with the office of a Mediator, and his suretyship engagements for them, which were from eternity; and are the ground, and foundation of his being in them, and they in him in the effectual calling; nor does it suggest that they shall begin to be known; only that they shall be known in a more perfect manner: the time when this will be, is "at that day": meaning either when he should "live" in the body again, be raised from the dead, when he should he declared to be the Son of God with power, when it would appear, that he had the same power with the Father, by raising himself from the dead, and when he would rise as a public head representing them, for their justification, and they should see themselves justified and discharged in him; or the day of "Pentecost", when "the Spirit of truth", he promises to pray for, should come to them in an extraordinary manner, and lead them into the knowledge of these things; or the last day, the resurrection morn, when, by virtue of union to Christ, the saints shall rise and "live" with him for ever, and shall have a perfect knowledge of these several unions; see John 17:21.