The resurrection of Jesus Christ from the dead to spirit life was the greatest demonstration ever of God’s power. Without it, Christian faith would be “in vain,” his followers would be “of all men most to be pitied.” (1Co 15:12-19) It was the act most consistently recounted by Jesus’ disciples and the greatest single factor in strengthening faith. Distance had not hindered Jesus’ exercise of power when on earth (Mt 8:5-13; Joh 4:46-53), and now, from his heavenly position, Jesus anointed his followers with God’s spirit on Pentecost, enabling them to do powerful works in his absence. He thereby authenticated their testimony concerning his resurrection (Ac 4:33; Heb 2:3, 4) and also gave proof that these were God’s approved people, his congregation.​—Ac 2:1-4, 14-36, 43; 3:11-18.

The death of his Son as a human had not shortened Jehovah’s hand, as the many miracles, signs, and portents performed by the apostles and others testified. (Ac 4:29, 30; 6:8; 14:3; 19:11, 12) The powerful works they performed were like those of their Master, healing the lame (Ac 3:1-9; 14:8-10) and ill (Ac 5:12-16; 28:7-9), raising the dead (Ac 9:36-41; 20:9-11), casting out demons (Ac 8:6, 7; 16:16-18), doing so without seeking personal benefit or honor for themselves. (Ac 3:12; 8:9-24; 13:15-17) Through them God expressed judgments against wrongdoers, even as he had done through the earlier prophets, fostering due respect toward himself and his representatives. (Ac 5:1-11; 13:8-12) New abilities were granted them, such as the ability to speak in foreign languages and interpret them. This, too, was for “a beneficial purpose,” for they were soon to extend the preaching work beyond Israel, telling Jehovah’s wonderful works among the nations.​—1Co 12:4-11; Ps 96:3, 7.

Jehovah God did other powerful things as well, opening up ‘doors’ of opportunity for them to preach in certain territories, protecting them against those who would shut down their ministerial work, directing their activity, doing so in ways generally unobserved by the public.​—Ac 5:17-20; 8:26-29, 39, 40; 9:1-8; 10:19-22, 44-48; 12:6-11; 13:2; 16:6-10, 25-33; 18:9, 10; 1Co 16:8, 9.

Relative importance of miraculous acts. Although Jesus laid principal stress on the truths he proclaimed, he nevertheless showed the relative importance of his powerful works, regularly calling attention to them as authenticating his commission and message. Their importance lay particularly in their fulfillment of prophecy. (Joh 5:36-39, 46, 47; 10:24-27, 31-38; 14:11; 20:27-29) Those seeing such works came under special responsibility. (Mt 11:20-24; Joh 15:24) As Peter later told the crowds at Pentecost, Jesus was “a man publicly shown by God to you through powerful works and portents and signs that God did through him in your midst, just as you yourselves know.” (Ac 2:22) These evidences of divine power showed that God’s Kingdom had “overtaken” them.​—Mt 12:28, 31, 32.

By God’s significant use of his Son, the ‘reasonings of many hearts were uncovered.’ (Lu 2:34, 35) They were seeing ‘the arm of Jehovah’ manifested, but many, the majority, preferred to read some other meaning into the events beheld or to allow selfish interests to keep them from acting in harmony with the ‘sign’ seen. (Joh 12:37-43; 11:45-48) Many wanted personal benefits from God’s power but were not sincerely hungering for truth and righteousness. Their hearts were not moved by the compassion and kindness that motivated so many of Jesus’ powerful works (compare Lu 1:78; Mt 9:35, 36; 15:32-37; 20:34; Mr 1:40, 41; Lu 7:11-15 with Lu 14:1-6; Mr 3:1-6), which compassion reflected that of his Father.​—Mr 5:18, 19.