During His discourse in John chapter 7, Jesus spoke of the future ministry of the Holy Spirit (John 7:39; cf. John 15:26; 16:7), which would occur after His resurrection and ascension on the Day of Pentecost (Acts 1:5; 2:1-4). The Holy Spirit was active in the lives of OT saints such as Artisans (Ex. 31:1-5), Judges (Num. 11:25-29; Jud. 3:9-10), Prophets (Ezek. 2:2), and Kings (1 Sam. 10:6; 16:13); however He did not indwell every believer, and could be removed as an act of divine discipline (1 Sam. 16:14-16; Ps. 51:11). After Pentecost, the Holy Spirit’s ministry includes regeneration (John 3:1-6; 1 Pet. 1:3; 23), indwelling (1 Cor. 3:16; 6:19), baptizing (1 Cor. 12:13), sealing (Eph. 1:13-14; 4:30), gifting (1 Cor. 12:4-7), filling (Eph. 5:18), equipping (Eph. 4:11-16), and sustaining each believer (Gal. 5:16, 25). The work of the Holy Spirit is to lead us to spiritual maturity so that we may be effective in our ministries to others.