Repentance means to change one’s mind about something, such as God, self, way of life, or sin. The desired result is continued harmony and fellowship with God. The Greek verb is μετανοεω, metanoeo (Luke 10.13; Acts 17.30; 2 Corinthians 12.21; Revelation 2.21-22). The Greek noun is μετανοια, metanoia (Luke 5.32; Acts 20.21; Romans 2.4; Hebrews 6.1; 2 Peter 3.9).
Repentance has a wide theological scope: on one end it can be a broad call for a nation to return to her heritage and on the other end of the spectrum it can be a precise call for a believer to confess specific sin and return to fellowship with God.
Repentance is not a condition of salvation except when referring to the change of mind about Christ and salvation. Faith in Christ as Savior is the only condition for salvation (John 3.16; Acts 16.31; Ephesians 2.8-9). When one believes in Jesus Christ that one has changed his mind about Jesus Christ. He has repented. Repentance often leads to faith in Jesus Christ.
Both unbelievers (Matthew 12.41) and believers repent (Luke 15; Acts 19.18-20; 2 Corinthians 7.9-10 “to the point of repentance,” “leaving to salvation,” metanoia; Revelation 3.19).
When unbelievers repent, it does not mean that they have become believers. When in association with the gospel, it may mean a change of thinking about self, sin, and God. An unbeliever’s repentance may hold off God’s judgment or prepare him to listen more closely to the gospel (Matthew 12.41).
In the case of the believer, repentance may prepare for a confession of personal sin and return to fellowship; at times, it includes the confession of sin as illustrated by the Prodigal Son in Luke 15 (Luke 15; Acts 19.18-20; 2 Corinthians 7.7-10; Revelation 3.19).
Jesus and John the Baptist told Israel to repent. This was not a call to eternal salvation, but instead a call to return to the national relationship with God for which God had prepared them. The call to repentance was to prepare them to believe in their Messiah (Matthew 3.1-3; Luke 3.3, 8-9).
Jesus also told the Jewish people to repent from their rebellious political and religious activities; if they did not repent, temporal judgment, including physical death would result (Luke 13.1-9).
In summary, the command to repent is a call to change one’s thinking. It is a call for the unbeliever or the believer to change his thinking about God, self, way of life, or sin. Repentance is something we all do.