The Holy Spirit was not “created” with the inception of the New Testament church. Yes, He functions differently in this new age than He did in the old age, but as a member of the Triune godhead His nature is unchanging. What He is today, He always has been.
So how does the Old Testament refer to the Holy Spirit and what does the Old Testament reveal about His work?
He existed before time and creation (which is to say He was eternal) and He was part of the Triune work of creation (Gen. 1:2; Job. 26:13; Ps. 104:30).
He is revealed as sovereign over creation by the opening and closing of the Red Sea (Ex. 15:8-10)
He is the source of salvation life for Old Testament saints in bringing dead people to life in Ezekiel’s vision ( 37:9-10).
He restrained sin (Gen. 6:3, 5; 8:21; Jer. 17:9//Jn. 16:8).
He empowered and equipped Old Testament saints spiritually (and even “naturally”) (Num. 11:17; Ex. 28:3).
He transformed hearts (Dt. 30:6; Ezk. 36:25-27).
He was the source of inspiration of Scripture (2 Sam. 23:1-3; Neh. 9:30).
He bore names indicative of His eternal deity: Spirit of Strength (Is. 11:2), Spirit of the fear of the Lord (Is. 11:2), Spirit of God (Gen. 1:2), Willing Spirit (Ps. 51:12), Spirit of Grace and Supplication (Zech. 12:10), and Spirit of Wisdom, Understanding, Counsel, and Knowledge (Ex. 28:3; Is. 11:2).
He bore attributes indicative of His eternal deity: He was omnipresent (Ps. 139:7-10), omnipotent (Job 33:4), and wise (Is. 40:13).
While the Holy Spirit functioned differently in the Old Testament than the New Testament (e.g., He did not inhabit all believers perpetually as He does now; Gen. 41:38; Judges 3:10: 6:34; 11:29; 14:26; 1 Sam. 10:10; 16:13-14; Ps. 51:11), He was, is, and will always be fully God, undiminished in every aspect of His deity. He functions differently today, but the Holy Spirit is the same yesterday, today, and forever.
“Gold Pour” by Juancarlos Casas Gutierrez from New York, USA, CC BY 2.0, via Wikimedia Commons.