In Scripture, we learn that the Holy Spirit is God (Gen 1:2; Acts 5:3-4), and He always directs believers to think and act in a manner consistent with His holy character. Under the Mosaic Law, only a select few persons received the Holy Spirit (Ex 31:1-5; Num 11:25; 27:18; 1 Sam 16:13), and that was conditioned on God’s sovereign purposes. Merrill F. Unger states:
- "In Old Testament times the Spirit sovereignly came upon a few. Warriors, kings, prophets, and mighty men were temporarily filled to perform some special task, such as Gideon (Judg 6:34), Amasai (1 Ch 12:18), Samson (Judg 14:6), and Saul (1 Sam 16:13). Pentecost, however, marked a new era in which every believer, no matter how poor, humble, or obscure, might be constantly “filled with the Spirit.” This is the reason for the stress upon the infilling (Acts 2:4). What warriors, kings, prophets and mighty men then enjoyed only temporarily can now be enjoyed by every believer constantly (Acts 2:17–18)."
Under the Mosaic Law, the ministry of the Holy Spirit was conditioned upon holiness and could be forfeited due to heinous sin (Judg 16:20; 1 Sam 16:14-16; Psa 51:11); however, the removal of the Holy Spirit as an act of discipline did not mean forfeiture of salvation (Judg 16:28-30; 1 Sam 24:6, 10; 2 Sam 1:14-16; cf. Heb 11:32). During the Church age, the Holy Spirit convicts the unsaved about sin, righteousness, and judgment (John 16:8-11). The specific sin mentioned by Jesus is that of unbelief that He is the Savior.
The indwelling ministry of the Holy Spirit for every believer was an innovation that was future from the time of Jesus’ ministry on earth (John 14:16-17; 16:7, 13). In the church age, all three Persons of the Godhead indwell every believer (John 14:16-17, 20, 23); however, the Holy Spirit has a special ministry which began on the day of Pentecost (Acts 1:4-5; 2:1-4; 11:15-16; 1 Cor 12:13; Gal 3:26-28), and will continue until the church is raptured to heaven (2 Th 2:7; cf. John 14:1-3; 1 Th 4:13-18; Tit 2:13). According to Thomas Constable:
- "The Holy Spirit of God is the only Person with sufficient (supernatural) power to do this restraining…How does He do it? Through Christians, whom He indwells and through whom He works in society to hold back the swelling tide of lawless living. How will He be taken out of the way? When the church leaves the earth in the Rapture, the Holy Spirit will be taken out of the way in the sense that His unique lawlessness-restraining ministry through God’s people will be removed (cf. Gen 6:3)."
The Holy Spirit brings about our spiritual birth (John 3:3, 6-7; cf. 1 Pet 1:2-3, 23), baptizes us into union with Christ (1 Cor 12:13), indwells us (1 Cor 3:16; 6:19), and is Himself the seal (σφραγίζω sphragizo – a mark of ownership) that guarantees our future redemption and glory (Eph 1:13-14; 4:30). These blessings are completely the work of the Holy Spirit for the benefit of the Christian and occur at the moment of faith in Christ. These are facts based on objective statements in Scripture and are accepted by faith, not our subjective feelings. As Christians, we can grieve and/or quench the Holy Spirit with personal sin (Eph 4:30; 1 Th 5:19), and though we may suffer divine discipline because of personal sin (Heb 12:5-11), we cannot grieve Him away. The Holy Spirit works in the life of every Christian to glorify Jesus (John 16:14), to reveal Scripture directly and through gifted teachers (John 16:13-15; Eph 4:11-16), to illuminate Scripture and make it understandable/acceptable (1 Cor 2:11-13), and to promote the use of the believer’s spiritual gift for the edification of others (Rom 12:6-8; 1 Cor 12:4-10, 28-30; Eph 4:11; 1 Pet 4:10).
 Merrill F. Unger, “The Significance of Pentecost” Bibliotheca Sacra (1965): 174.
 Thomas L. Constable, “2 Thessalonians,” in The Bible Knowledge Commentary: An Exposition of the Scriptures, ed. J. F. Walvoord and R. B. Zuck, vol. 2 (Wheaton, IL: Victor Books, 1985), 719.