John 14:20 Meaning and Explanation

At that day. Jesus points forward to the resurrection, Pentecost, and the new mode of presence that will follow. On that day, a clarity will come. Not intellectual understanding alone but spiritual recognition. Ye shall know. The disciples will see him raised and recognize that death has no power over him. They will receive the Spirit and feel his presence within them. The veil between the invisible and visible will grow thin. I am in my Father. The unity of Jesus and the Father will become undeniable. The one who seemed to die proved to be indestructible because he was one with the one who cannot die.

And ye in me, and I in you. Here is the vast mystery of the Christian faith compressed into a sentence. We are in Christ; Christ is in us. We exist in him as branches exist in a vine, drawing life and sustenance from him. He dwells in us through the Spirit, transforming us from within. This is not mere metaphor. It is the central claim of the Gospel: that the separation between God and humanity caused by sin is healed in the person of Christ. Through faith, we are grafted into his life, and he makes his home in ours. This is why the New Testament can speak of Christians being 'saved' and yet also 'being saved,' as if it is both a past event and an ongoing reality. We are continuously united to Christ, continuously receiving his life, continuously being transformed by his presence.