The premise of Biblical repentance is an exchanging of one's mind for the mind of Christ... that is, a change of mind that acknowledges one's sin of un-belief concerning the revelation of God's Word and their need of God's mercy resulting in a willful and direct turn to the Lord Jesus Christ by faith for the atonement of their sin (1 John 2:2). Thus, a changed life is wrought by the power of the gospel of Jesus Christ and the indwelling of the Holy Spirit (2 Corinthians 5:17).
We are not talking about turning from un-belief to belief. Rather, we are talking about turning from the sin that unbelief is and turning to Christ Jesus through faith for the forgiveness of sin. Unbelief is not saying there is no God, it is the sin of saying I don't need or want God. (Genesis 3:1,6). Repentance is turning from sin while faith is turning to God. It is possible to repent from sin and not turn to God in faith and remain unsaved. It is, however, impossible to turn to God by faith without repentance from sin, thus a religious sinner. (2 Corinthians 7:10). Faith and repentance are made possible by the Grace of God and are therefore, inseparable in the reality of salvation (Ephesians 2:8,9).
Repentance Is Not an act of reformation (work for salvation), nor is it an attitude of remorse that merely wrestles with regret (as did Judas). Repentance has for its strength the convicting Word of God by the person of the Holy Spirit who enables the sinner to realize their sin and its consequence of eternal separation and damnation from God, while articulating the simplicity of faith in Christ Jesus who is the only means of salvation (John 16:7-11; Acts 4:12).
Rev William A Tyler Sr