After Jesus left earth, the Holy Spirit came to enable believers to resist sin and fulfill God’s mission. He existed from the beginning and throughout the Old Testament (Genesis 1:2; Numbers 11:9; Job 34:14-15; Psalm 104:30; Isaiah 32:14-18, 44:3; Joel 2:28-29)—but since Acts, he has been present with us in a new way, as promised by both John the Baptist and Christ (Matthew 3:11; John 16:7; Luke 24:49; Acts 1:8). He purifies, unifies, illuminates / instructs, and empowers (2 Thessalonians 2:18; 1 Corinthians 12:13; John 14:26; Acts 2).