But why does He speak of life as present to Him, future to them? Because His resurrection preceded, theirs was to follow. His resurrection was about so soon to take place, that He speaks of it as present; theirs being deferred till the end of the world, He does not say ye live, but ye shall live. Because He lives, therefore we shall live: As by man came death, by man came also the resurrection of the dead. (1 Cor. 15:21) It follows: In that day (the day of which He saith, ye shall live also) ye shall know, i. e. whereas now ye believe, then ye shall see, that I am in the Father, and ye in Me, and I in you. For when we shall have attained to that life in which death is swallowed up, then shall be finished that which is now begun by Him, that He should be in us, and we in Him.
Reproduced in full. Translation: Oxford 1841 (Newman), public domain (Public domain).
Also cites: Tr. lxxv. 3