John 14:20 says, “At that day you will know that I am in my Father, and you in me, and I in you.” Jesus had told his disciples he was going away. He illustrated his death by the bread and the cup at Passover. They didn’t understand. Philip asked him, “Lord, show us the Father and it is sufficient” (14:8). Jesus appealed to his miracles and words (vs. 10-11) asking, “Do you not believe that I am in the Father, and the Father in me?” They didn’t. Now he says they “will know at that day,” i.e., his resurrection. Even more, he said they will know they are “in me, and I in you.” Notice: all of us in him and he in all of us! Complete sinless unity with Jesus forever! Assurance comes from the indwelling “Helper” (v. 15), the Holy Spirit. They got it. So did we. Praise him today!