“This Jesus God raised up, and of that we all are witnesses. Being therefore exalted at the right hand of God, and having received from the Father the promise of the Holy Spirit, he has poured out this which you see and hear. For David did not ascend into the heavens; but he himself says, ‘The Lord said to my Lord, Sit at my right hand, till I make thy enemies a stool for thy feet.’ Let all the house of Israel therefore know assuredly that God has made him both Lord and Christ, this Jesus whom you crucified.” Now when they heard this they were cut to the heart, and said to Peter and the rest of the apostles, “Brethren, what shall we do?” And Peter said to them, "Repent, and be baptized every one of you in the name of Jesus Christ for the forgiveness of your sins; and you shall receive the gift of the Holy Spirit. For the promise is to you and to your children and to all that are far off, every one whom the Lord our God calls to him." And he testified with many other words and exhorted them, saying, "Save yourselves from this crooked generation." So those who received his word were baptized, and there were added that day about three thousand souls. And they devoted themselves to the apostles' teaching and fellowship, to the breaking of bread and the prayers.
(Acts 2:32-42)

Jesus says in Acts 1:5 and 8 that baptism in the Spirit means, "You shall receive power . . . and you shall be my witnesses." This is an experience of boldness and confidence and victory over sin. A Christian without power is a Christian who needs a baptism in the Holy Spirit. 

First, the Word of God must be heard. Peter has preached that in God's plan, Jesus was crucified, raised, and exalted as Lord over all the universe and that forgiveness of sin and spiritual renewal can be had from Him. The Word has been heard.

Second, the sovereign God must call men and women to himself or they will never come. Verse 39:, "The promise is to you and to your children and to all that are far off, everyone to whom the Lord our God calls to him." No one comes to faith in Christ unless the Father draws him (John 6:4465). The preached Word is heard with conviction and power only when the effectual call of God lays hold on the hearers.

Third, we must "receive the word." Verse 41: "So those who received his word were baptized." Receiving the Word means that it becomes part of you so that you trust the Christ it presents. You trust His provision for your forgiveness. You trust His path for your life. You trust His power to help you obey. And you trust His promises for your future. And that radical commitment to Christ always involves repentance—a turning away from your own self-wrought provisions and paths and powers and promises. And when you really turn to Christ for new paths and new power, you open yourself to the Holy Spirit, because it is by His Spirit that Christ guides and empowers.

Finally, we must give an open expression of faith in the act of water baptism in obedience to Jesus Christ. Baptism was the universal experience of all Christians in the New Testament. There were no unbaptized Christians after Pentecost. Christ had commanded it (Matthew 28:18) and the church practiced it. So we do today.

Therefore, we invite you to experience the greatest thing in the world. Repent, trust Christ, open yourself to the power of His Spirit, be baptized in His name, and you will receive the gift of the Holy Spirit.