The Comforter (v.16) was “the Spirit of God” (Mt.3:16), but also “the Spirit of Christ” (IPe.1:11), which is why the Lord called Him “the Spirit of truth” (Jo.14:17). He had just told them that He was “the truth” (v.6), so the Spirit would be “the Spirit of truth.” This was His way of telling them that the Spirit would be His continued presence among them (Mt.28:20).
This is why the Holy Spirit is sometimes called the Holy Ghost. There are ghosts (Gen.25:8; Lu.24:37-39), they just aren’t allowed to walk among us. By calling the Spirit “the Holy Ghost” the translators were trying to convey what the Lord was saying here, that the Spirit would be His lingering presence on earth. He was the truth, now the Spirit would be the Spirit of truth.
Saying that the world couldn’t receive the Spirit “because it seeth Him not, neither knoweth Him” (v.17) implies that the 12 could see and know Him. They saw Him in Christ. Just as the Father could be seen and known in the Son (14:7,9), so could the Spirit. That’s how the Lord could say of the Spirit, “but ye know Him; for He dwelleth with you.” The Spirit dwelt with them in Christ (Jo.3:34).
But He was about to dwell “in” them (v.17) at Pentecost. When the Lord went on to say, “I will come to you” (v,18), He meant that He would come to them in the Spirit at Pentecost.
In saying that the world would see Him no more after He died, but that they would see Him (14:19), He meant that they would see Him in the Spirit (Jo.16:16). And because He lived, they will live (v.19 cf. John 6:57).
In context, “that day” (14:20) is a reference to the day of Pentecost. He’d already told them that He was in the Father (10:38), even as recently as a few verses ago (14:10), but they didn’t fully get it, so He says here that “at that day ye shall know that I am in My Father.” They were perfect examples of what the Lord was trying to illustrate by restoring sight to the blind man gradually (Mark 8:22-26). He was teaching them that God’s people would not see everything clearly until the kingdom (Isa.29:18; 32:1-3), and Pentecost was the beginning of the kingdom.
At Pentecost they would also know that they were in Christ (14:20). They weren’t in the Body of Christ, of course, for that “new man” began with Paul (Eph.2:14,15). Paul spoke of those in Christ before him (Rom.16:7) because all men are either in Adam or in Christ (ICor.15:22). Abraham and David were in Christ, they just didn’t know it. But their hope was to live again on earth, while the hope of the Body is to be raptured. At Pentecost they would also know that Christ was in them (14:20). Christ has always indwelt believers (John 6:56).
If you are not saved, when the Lord said “yet a little while, and the world seeth Me no more” (v.19), maybe you thought you’d never have to face the One who died for you. If so, you should know that if you miss the Rapture and live to see the Second Coming, “every eye shall see Him” (Rev.1:7). So what did the Lord mean when He said that the world would see Him no more?
Well, He also told the disciples that they would see Him no more (John 16:10), even though He knew they would see Him again in the kingdom. He meant that they would see Him no more as the humble carpenter’s son. When they saw Him again, it would be as “the Lord of glory” (James 2:1). If you are not saved, you too will see the Lord someday, but in that day He will be your judge, not your savior (James 5:9).
When they crucified the Lord, the world thought that He would never be able to judge them, but God assured them otherwise when He raised Him from the dead (Acts 17:30,31). So don’t be thinking that you will get away with your sins just because men did away with your judge. He is alive, and if you refuse His payment for your sins, you must pay for your sins in the lake of fire for all eternity.
The choice is yours.