What is repentance?

In Peter's famous Pentecost sermon, the crowds were cut to the heart and asked him, "What shall we do?" and he replied, "Repent and be baptized every one of you in the name of Jesus Christ for the forgiveness of your sins . . ." (Acts 3:38). From that time forward, the Church has called all people everywhere to repentance, faith and baptism. Yet the question must be asked, What is repentance?

John Piper, in a recent post, answered it well in a single sentence:

There is no clear dividing line between biblical repentance and Christ-exalting civic engagement.

In other words, the repentance required is to be lived out in the daily realities of families, vocation, communities and nations. It entails supreme allegiance to Jesus as King, not just as a theological doctrine, but in practical obedience. Hence Jesus' command, "Render unto Caesar the things that are Caesar's, and to God the things that are God's," and John the Baptist's eminently practical counsel to those who asked what it meant to bear fruit in keeping with repentance:

And the crowds asked him, “What then shall we do?” And he answered them, “Whoever has two tunics is to share with him who has none, and whoever has food is to do likewise.” Tax collectors also came to be baptized and said to him, “Teacher, what shall we do?” And he said to them, “Collect no more than you are authorized to do.” Soldiers also asked him, “And we, what shall we do?” And he said to them, “Do not extort money from anyone by threats or by false accusation, and be content with your wages.” (Luke 3:10-14)

For those of us who have inherited a 'separation of church and state' mentality, this is itself a call to repentance. An essential step in repentance is to recognize and repent of this assumption that the gospel is a private, personal, inward matter of faith in Christ, and not a public repentance in our civic engagement.