John 14:16-18 And I will pray the Father, and He shall give you another Comforter, that He may abide with you forever; even the Spirit of truth; whom the world cannot receive, because it seeth Him not, neither knoweth Him: but ye know Him; for He dwelleth with you, and shall be in you. I will not leave you comfortless: I will come to you.
In preceding verses, Jesus pleads for His apostles to believe Him to be the Son of God, as well as, trust and accept Him for His teachings and His compassionate miracles, which He performed in the name of God. With this strong, unwavering belief in Him, Jesus told them that If ye love Me, keep My commandments (See Prev. Vss. 12-14). Then in the lesson text, Jesus proceeds to tell His apostles that He will intercede for them and pray to His Father in heaven for them. This intercession will take place, not immediately, but after His death, burial, resurrection, and ascension back into heaven. It is well to note here that Jesus, as He is seated at the right hand of God, constantly, and in the same manner of intercession, pleads with God on our behalf (See Rom. 8:34; Heb. 4:14-15).
In answer to His prayer of intercession for them, Jesus assured His apostles that God would send them another Comforter. While with them here on earth, Jesus had been their Comforter - their friend, leader, teacher, guide, protector, counselor, and provider of all their physical and spiritual needs. The word translated as "Comforter" refers to a helper of others, one that gives aid to those in need, and specifically, one that serves as an advocate rendering advice on legal compliance. The promised Comforter, Jesus told His apostles, would abide with you forever. As their comforting, spiritual leader, Jesus was with His apostles three plus years, but the Comforter to come and replace Him, was promised to be their all-wise, spiritual leader for the remainder of their life on earth.
This Comforter is also identified as the Spirit of truth, and in verse 26 of this same chapter, John identifies this heavenly being as the Holy Ghost. In verse 26 of the following chapter of this gospel, John, once again refers to the Comforter as God's Spirit of truth - that is, the Holy Spirit of God. Matthew 28:19 introduces us to the triumvirate, which is widely known on earth as the Holy Trinity, and includes the Father, and of the Son, and of the Holy Ghost. God is our Heavenly Father and the Creator of all things, including mankind, whom He made in His own image. The Son of God is Christ Jesus, whom He sent to earth to experience human life as all other men and women of the world, and serve as the atoning sacrifice by which sins may be forgiven and reconciliation to our sinless God could be attained. The Holy Ghost is also known, as noted above, as the Holy Spirit of God, and the Comforter, having the divine responsibility of leading, counseling, and instructing the apostles of Christ, enabling them to teach God's plan of eternal salvation through Christ Jesus and establish His church through which the hope of salvation could be attained.
The Comforter, the Holy Spirit, is God's advocate; He explained His New Covenant law, not only to the apostles of Jesus, but to all disciples of Christ whom He inspired to write His New Testament Holy Word. From these scriptures, the Comforter - the Deliverer of God's word to earth, also serves as our spiritual instructor, and teaches all men and women of the world God's plan of salvation, and how it may be attained.
The Comforter, ...the Spirit of truth, will be rejected by the unbelieving world because it seeth Him not, neither knoweth Him. The only place the Holy Spirit can be found in an individual is in his or her heart. The world is led by sight and not by faith, therefore it is impossible for them to know Him because they cannot see Him. Since the Holy Spirit of God taught Jesus' apostles and teaches His Christian followers today, He is said to dwell in each Christian. Unbelievers reject the teaching of God's word, and therefore they do not know the Holy Spirit nor are they comforted by His advocacy with God through Christ Jesus. A spiritual being cannot be seen, only evidenced in one that is being led by His teaching. Again Jesus gives His apostles this encouragement: I will not leave you comfortless. In His absence He will send the Comforter to sustain them for the rest of their lives on earth, after which He assured them that I will come to you, referring to His second coming on Judgment Day. What a comforting promise was given to His apostles in the lesson text. Even greater, this same comfort is promised to each obedient Christian today.