Isa 44:3, Joel 2:28, Jn 1:33, Jn 14:16, Acts 5:32
In the Old Testament it was promised that God would pour out the Holy Spirit. (Isa 44:3, Joel 2:28)
Isa 44:3 For I will pour water upon him that is thirsty, and floods upon the dry ground: I will pour my spirit upon thy seed, and my blessing upon thine offspring:
Joel 2:28 And it shall come to pass afterward, that I will pour out my spirit upon all flesh; and your sons and your daughters shall prophesy, your old men shall dream dreams, your young men shall see visions:
Jesus is the one who will baptize you with the Holy Spirit. (Jn 1:33)
Jn 1:33 And I knew him not: but he that sent me to baptize with water, the same said unto me, Upon whom thou shalt see the Spirit descending, and remaining on him, the same is he which baptizeth with the Holy Ghost.
God pours out the Holy Spirit on those who believe in Jesus as the Christ. (Jn 7:37-39, Jn 14:16)
Jn 7:37 In the last day, that great day of the feast, Jesus stood and cried, saying, If any man thirst, let him come unto me, and drink. 38 He that believeth on me, as the scripture hath said, out of his belly shall flow rivers of living water. 39 (But this spake he of the Spirit, which they that believe on him should receive: for the Holy Ghost was not yet given; because that Jesus was not yet glorified.)
Jn 14:16 And I will pray the Father, and he shall give you another Comforter, that he may abide with you for ever;
The Holy Spirit is poured out on those who believe in Jesus as the Christ. (Act 5:30-32)
Act 5:30 The God of our fathers raised up Jesus, whom ye slew and hanged on a tree. 31 Him hath God exalted with his right hand to be a Prince and a Saviour, for to give repentance to Israel, and forgiveness of sins. 32 And we are his witnesses of these things; and so is also the Holy Ghost, whom God hath given to them that obey him.