Jesus’ resurrection from the dead proved that God accepted his sacrifice for our sins as the Lamb of God. He rose in power as the Lord of Lords, having stripped Satan of his authority and power.

and he was shown to be the Son of God when he was raised from the dead by the power of the Holy Spirit. He is Jesus Christ our Lord. Romans 1:4 (NLT)

When our Lord ascended into heaven forty days after his resurrection, he vanished from his disciples’ sight. Ten days later, on the exact day of the feast of Pentecost, the Holy Spirit was poured out on the disciples in the upper room. This proved that Jesus had been enthroned in heaven, from where he kept his promise to send the Spirit. (Acts 1:4-8)

Peter included the outpouring of the Spirit in the first gospel message ever preached by the apostles, making it part of the gospel.

Therefore having been exalted to the right hand of God, and having received from the Father the promise of the Holy Spirit, He has poured forth this which you both see and hear. Acts 2:33 (NASB) 

Jesus is now ruling from heaven as Lord of the Harvest, having commissioned his followers to preach the gospel and make disciples all over the world until his return. This fulfilled John the Baptist’s prophecy that Jesus would baptize people in the Holy Spirit and fire. (Luke 3:16) The Spirit baptism empowers and equips God’s people to be Great Co-Missionaries and is a promise God wants every child of God to receive. This is integral to the message of the gospel.

To read more about the baptism in the Holy Spirit, click here.