There are three ways people may respond to the gospel: apathy, hostility, or interest. In the category of interest, there are the possibilities of a passionate response or a measured one. Peter’s hearers ardently responded, which was the best possible outcome.

Now when they heard this, they were pierced to the heart, and said to Peter and the rest of the apostles, "Brethren, what shall we do?" 38  Peter said to them, "Repent, and each of you be baptized in the name of Jesus Christ for the forgiveness of your sins; and you will receive the gift of the Holy Spirit.Acts 2:37-38 (NASB)

When the Holy Spirit opens someone’s heart, there will be a positive response to the gospel. We should be ready to tell them what to do next, if the opportunity presents itself.

Peter gave clear instructions to his respondents.

• Repent – Repentance is the proper response to the message that Jesus is Lord. It means we acknowledge Jesus’ claim to be Lord and willingly submit our lives to him.
• Be baptized in water – Water baptism is a public declaration of  faith – our trust in and allegiance to Christ. It is an outward expression of a heartfelt faith and allegiance.
• Receive the baptism or gift of the Holy Spirit – This baptism is separate from the new birth and is performed by Christ himself. It equips and empowers disciples to be bold witnesses.

These three steps will launch the new convert into his or her discipleship journey.