"Most assuredly, I say to you, he who believes in Me, the works that I do he will do also; and greater works than these he will do, because I go to My Father. And whatever you ask in My name, that I will do, that the Father may be glorified in the Son. If you ask anything in My name, I will do it. If you love Me, keep My commandments. And I will pray the Father, and He will give you another Helper, that He may abide with you forever--the Spirit of truth, whom the world cannot receive because it neither sees Him nor knows Him; but you know Him, for He dwells with you and will be in you. I will not leave you orphans; I will come to you."
Those who had faith in Jesus would be imitators of His great works - "He who believes in Me, the works that I do he will do also." In fact, Jesus foretells that His followers would do "greater" works than He did. Certainly this does not mean that the apostles would perform more impressive miracles than had already been performed by Jesus (what could be more impressive than raising the dead?). It does mean that these apostles would soon begin a worldwide mission that was much larger in scope and success. On the Day of Pentecost, a glimpse of these "greater" works was seen in the number of conversions that day (i.e., 3000 souls; cf. Acts 2:41). Jesus, during His entire earthly ministry, may have made only 500 disciples approximately (cf. I Cor. 15:6). The church of the first century, before 70 A.D., took the gospel "to every creature under heaven" (Col. 1:23). Certainly these are examples of the "greater" works Jesus here refers to.
"Whatever you ask in My name, that I will do" - Prior to this time (cf. John 16:24), prayer had not been made in Jesus' name (i.e., by His authority). God would glorify Himself through Christ by answering such prayers. Of course, one would be wise to remember that Jesus' words here are limited to those things asked according to His will (cf. I John 5:14).
"If you love Me, keep My commandments" (John 14:15). This thought is found repeatedly in this context and elsewhere in the New Testament (cf. 14:21,23,24; 15:10; I John 5:3; II John 6). Although Jesus would be leaving soon and would no longer be present in the flesh to guide them, it was still imperative that they continue living obediently. It is useless for one to profess a love for God while refusing to do what He says. Jesus is "the author of eternal salvation to all who obey Him" (Heb. 5:8,9). All who truly love the Lord will obey Him!
"He will give you another Helper, that He may abide with you forever" - Jesus had been a "Helper" (or Advocate, cf. I John 2:1) for them for several years, and they would not be left alone when He departed. The Holy Spirit (cf. John 14:26) would be another "Helper" for them, and He would never depart from them. At this point, Jesus has not described the kind of help that the Holy Spirit would provide. He has simply pointed out, to encourage them, the fact that they would not be without aid.
It should be observed that John 14:16 proves that Jesus and the Holy Spirit are also distinct (contrary to the claims of some Pentecostal groups). How could the Holy Spirit be "another" Helper if He was the same exact being as Jesus?
The Holy Spirit is likely called "the Spirit of truth" because of His important role in the revelation of divine truth (cf. 14:26; II Pet. 1:20,21).
The world cannot "receive" the Holy Spirit because the world doesn't obey (i.e., love) God (cf. 14:15). If the world did "know" God, then they would obey Him (cf. I John 2:3-5). Some believe that the word "receive" is better translated as "take." This would shift the emphasis to the fact that the world could not forcefully take or remove this Helper from the disciples (as they were about to do with Jesus).
An examination of the wording here indicates that the Holy Spirit was already dwelling with them (presumably He was present, like the Father, through the Person of Christ), but soon He would be in them (cf. John 7:38,39; Acts 2:38; 5:32; etc.).
Jesus promised - "I will not leave you orphans; I will come to you." Although He was about to depart, He was not abandoning them. It is true that He Himself would see them again, however, it seems likely that the meaning here is that He would "come" to them through His agent, the Holy Spirit.