Is the Holy Spirit manifest during the Old Testament? If so, why did Jesus say that He will send the Holy Spirit?

---

After David sinned he penned Psalm 51 and as a prayer added: Ps. 51:11 “Do not cast me away from Your presence, And do not take Your Holy Spirit from me.” Isa. 63:10 But they rebelled and grieved His Holy Spirit; So He turned Himself against them as an enemy, And He fought against them. 11 Then he remembered the days of old, Moses and his people, saying: “Where is He who brought them up out of the sea With the shepherd of His flock? Where is He who put His Holy Spirit within them,” It seems clear that the Godhead represented by the Holy Spirit was present throughout the history of man to direct them. Luke 4:1 “Then Jesus, being filled with the Holy Spirit, returned from the Jordan and was led by the Spirit into the wilderness” The Holy Spirit like a dove came down on Jesus as He was willing to allow the power sent by His Father to fully direct His life. Matt. 3:16 “When He had been baptized, Jesus came up immediately from the water; and behold, the heavens were opened to Him, and He saw the Spirit of God descending like a dove and alighting upon Him. 17And suddenly a voice came from heaven, saying, “This is My beloved Son, in whom I am well pleased.” All three of the Godhead present at His baptism. The Godhead with the Holy Spirit was also present at creation. Gen. 1:1 “In the beginning God created the heavens and the earth. 2The earth was without form, and void; and darkness was on the face of the deep. And the Spirit of God was hovering over the face of the waters.” The role or involvement of the Holy Spirit changed, deepened after Christ’s work of salvation was completed on the Earth. John 7: 39 “But this He spoke concerning the Spirit, whom those believing in Him would receive; for the Holy Spirit was not yet given, because Jesus was not yet glorified.” Jesus being God also became permanently man and lost one of His godlike attributes namely omnipresence and He was limited by the fact that He could only influence people is His immediate presence. He alluded to a new role for the Holy Spirit that His Father will send to help to solve the sin problem. John 14:16 “And I will pray the Father, and He will give you another Helper, that He may abide with you forever—“ John 14:25 These things I have spoken to you while being present with you. 26But the Helper, the Holy Spirit, whom the Father will send in My name, He will teach you all things, and bring to your remembrance all things that I said to you.” Here we see that the Holy Spirit will become a Representative of Jesus as to remind His followers of what He taught and to direct them apart from His normal influence He had from creation. He will prepare a people for Christ to be His bride, the church of the New Testament. John 15:26 But when the Helper comes, whom I shall send to you from the Father, the Spirit of truth who proceeds from the Father, 1 John 5:6He will testify of Me. 27And you also will bear witness, because you have been with Me from the beginning.” John 17:7 “Now they have known that all things which You have given Me are from You. 8For I have given to them the words which You have given Me, and they have received them, and have known surely that I came forth from You, and they have believed that You sent Me. 9“I pray for them. I do not pray for the world but for those whom You have given Me, for they are Yours. 10And all Mine are Yours, and Yours are Mine, and I am glorified in them. 11Now I am no longer in the world, but these are in the world, and I come to You. Holy Father, keep through Your name those whom You have given Me, that they may be one as We are. 12While I was with them in the world, I kept them in Your name. Those whom You gave Me I have kept; and none of them is lost except the son of perdition, that the Scripture might be fulfilled. 13But now I come to You, and these things I speak in the world, that they may have My joy fulfilled in themselves. 14I have given them Your word; and the world has hated them because they are not of the world, just as I am not of the world. Here we have information to see that the Holy Spirit will do for the church that Christ would have done if He was personally present. It is tremendous news that the Godhead knew what we needed and Here the last prayer in the Bible: Rev 22:17 “And the Spirit and the bride say, “Come!” And let him who hears say, “Come!” And let him who thirsts come. Whoever desires, let him take the water of life freely.” We all long for the final homecoming and the Godhead confirms the power and support available from the ever-present Holy Spirit and like the servant in Genesis 24, bringing the virgin Rebecca to his master Isaac, the Holy Spirit will prepare the church to be ready with Christ’s second coming.