Mark 1:15 And saying, The time is fulfilled, and the kingdom of God is at hand: repent ye, and believe the gospel.
Jesus gives us our example of repentance. It is to turn to the gospel. It is to believe the gospel. It is to believe in the righteousness that He has promised and to turn from the works and conditions of self-righteousness. It is to turn from religion to God.
Acts 17:30 And the times of this ignorance God winked at; but now commandeth all men every where to repent: 31 Because he hath appointed a day, in the which he will judge the world in righteousness by that man whom he hath ordained; whereof he hath given assurance unto all men, in that he hath raised him from the dead.
Acts 20:21 Testifying both to the Jews, and also to the Greeks, repentance toward God, and faith toward our Lord Jesus Christ.
Acts 26:20 But shewed first unto them of Damascus, and at Jerusalem, and throughout all the coasts of Judaea, and then to the Gentiles, that they should repent and turn to God, and do works meet for repentance.
Ezekiel 14:6 Therefore say unto the house of Israel, Thus saith the Lord God; Repent, and turn yourselves from your idols; and turn away your faces from all your abominations.
Repentance. This word is primarily used to turn toward God. It is the action of the sinner to turn from there religion to the one true God. It is to turn from what you bring to God to what He brought to you. It is to turn to Jesus. It is for those whom God has revealed the righteousness of God who turn from their acts of righteousness. That is true biblical repentance. Yes, we should strive daily to turn from our daily sins but what is the sin that separates God’s people from all others, from the world? It is unbelief. It is the unbelief of the righteousness of God. It is as Paul would say the ignorance of righteousness in Romans 10. To not believe God is a sin.
John 16:8 And when he is come, he will reprove the world of sin, and of righteousness, and of judgment: 9 Of sin, because they believe not on me;
The examples above in Acts come from the Greek word that means to think differently. It is a change of mind. It is to believe. It is the movement of unbelief to belief. When our mind changes, we believe on Jesus. We believe God. What is the root of sin? It is unbelief. Adam did not believe the word of God. He disobeyed and ushered in death for us all. How can we prevail against unbelief? How can we repent from the sin of unbelief?
2 Timothy 2:25 In meekness instructing those that oppose themselves; if God peradventure will give them repentance to the acknowledging of the truth;
It is all of God.