Then in John 15, Jesus describes the indwelling further explaining that He (Jesus) is the vine and we are the branches, that we can do nothing apart from Him. We must dwell in Him and He in us. At the end of that chapter and in the next, He explains that when He leaves to go to the Father, He will send the Comforter (Holy Spirit):
Nevertheless I tell you the truth; It is expedient for you that I go away: for if I go not away, the Comforter will not come unto you; but if I depart, I will send him unto you. John 16:7
But of everything the Gospel of John has to say of the Holy Spirit and the mystery of the Trinity, the most overwhelming to me is in John 17 where Christ prays for us and explains the significance:
In Pauls testimony we can see the ministry of the indwelling Spirit:
For what man knoweth the things of a man, save the spirit of man which is in him? even so the things of God knoweth no man, but the Spirit of God.
Now we have received, not the spirit of the world, but the spirit which is of God; that we might know the things that are freely given to us of God. Which things also we speak, not in the words which man's wisdom teacheth, but which the Holy Ghost teacheth; comparing spiritual things with spiritual. But the natural man receiveth not the things of the Spirit of God: for they are foolishness unto him: neither can he know [them], because they are spiritually discerned. But he that is spiritual judgeth all things, yet he himself is judged of no man.
For who hath known the mind of the Lord, that he may instruct him? But we have the mind of Christ. I Corinthians 2:9-16
For the law of the Spirit of life in Christ Jesus hath made me free from the law of sin and death. For what the law could not do, in that it was weak through the flesh, God sending his own Son in the likeness of sinful flesh, and for sin, condemned sin in the flesh: That the righteousness of the law might be fulfilled in us, who walk not after the flesh, but after the Spirit.
For they that are after the flesh do mind the things of the flesh; but they that are after the Spirit the things of the Spirit. Romans 8:1-5
And unto the angel of the church in Sardis write; These things saith he that hath the seven Spirits of God, and the seven stars; I know thy works, that thou hast a name that thou livest, and art dead. Revelation 3:1
And out of the throne proceeded lightnings and thunderings and voices: and [there were] seven lamps of fire burning before the throne, which are the seven Spirits of God. Revelation 4:7
And I beheld, and, lo, in the midst of the throne and of the four beasts, and in the midst of the elders, stood a Lamb as it had been slain, having seven horns and seven eyes, which are the seven Spirits of God sent forth into all the earth. Revelation 5:6
An interesting discussion might be whether the Comforter, the Spirit of Truth, is one of the seven or the sum.
As a sidebar comment, the term spirit (not capitalized) is also a name for ministering angels:
But to which of the angels said he at any time, Sit on my right hand, until I make thine enemies thy footstool? Are they not all ministering spirits, sent forth to minister for them who shall be heirs of salvation? - Hebrews 1:13-14
These are passages that cause me to believe that we who have the indwelling Spirit will be raptured in advance of the Great Tribulation.
In this passage, I believe that the Holy Spirit is the one whose presence prevents the anti-Christ/false prophet from being revealed (emphasis mine):
Let no man deceive you by any means: for [that day shall not come], except there come a falling away first, and that man of sin be revealed, the son of perdition; Who opposeth and exalteth himself above all that is called God, or that is worshipped; so that he as God sitteth in the temple of God, shewing himself that he is God. Remember ye not, that, when I was yet with you, I told you these things?
And now ye know what withholdeth that he might be revealed in his time. For the mystery of iniquity doth already work: only he who now letteth [will let], until he be taken out of the way.
And then shall that Wicked be revealed, whom the Lord shall consume with the spirit of his mouth, and shall destroy with the brightness of his coming: - 2 Thessalonians 2:1-8
And at midnight there was a cry made, Behold, the bridegroom cometh; go ye out to meet him. Then all those virgins arose, and trimmed their lamps. And the foolish said unto the wise, Give us of your oil; for our lamps are gone out. But the wise answered, saying, [Not so]; lest there be not enough for us and you: but go ye rather to them that sell, and buy for yourselves.
And while they went to buy, the bridegroom came; and they that were ready went in with him to the marriage: and the door was shut.
Afterward came also the other virgins, saying, Lord, Lord, open to us. But he answered and said, Verily I say unto you, I know you not. Watch therefore, for ye know neither the day nor the hour wherein the Son of man cometh. - Matthew 25:1-13