God chose, before the foundation of the world, those who would be delivered from slavery to sin and those who would be condemned (Romans 8.28-30, 9.11-18). This election was not based on any merits of the elect, but on grace alone (Ephesians 1.4-6). Although all people deserve God's just punishment (Romans 3.23), God chose some to whom he would give the grace of repentance and saving faith in Christ for the forgiveness of sin before the world began. This act of election is an unconditional act of grace (Ephesians 2.8-9).
All people in the world are privileged to enjoy God's grace given to human beings. This grace is common, and is sufficient for daily life. Considering their sinful and fallen nature, all good things that human beings enjoy are works of God's common grace (Psalm 145.9). Saving grace, however, is reserved for those whom God had predestined to believe the gospel (Ephesians 2.5, 8-10). This grace is irresistible to those whom God has predestined, and is sufficient for the application of Christ's redeeming work performed on the cross for the forgiveness of sins (Colossians 1.20).
Repentance and Faith
Repentance and faith are gifts of God's grace given to believers and are necessary for salvation. Repentance is the act whereby a human being forsakes his or her desire for sinful tendencies as empowered by God (Acts 3.19, 26.20, 1 Corinthians 16.22). Those things loved in the sinful nature are forsaken for those things of a regenerated nature (1 Corinthians 5.9, 1 Thessalonians 2.4). Faith is God-given grace to believe the message of the gospel for the full forgiveness of sins. Through faith, God empowers individuals to believe that Christ's sacrifice is sufficient for justification and salvation, and that Christ's death and resurrection has secured for the believer all promises that are due to him or her through the act of being reconciled to God (Ephesians 2.8-9).
Justification refers to the standing sinners have before God after having had their sin paid for through the substitutionary atonement of Christ on the cross, having been declared not guilty on account of grace through faith in Christ (Romans 3.20, 28). God justifies the ungodly by faith and not by works (Romans 4.5, Galatians 3.24). God reckons as righteous and acceptable in his sight those whom he has granted the grace of faith, by which sinners are united to Christ, whose perfect righteousness is alone satisfactory for full justification (Romans 3.25, 1 John 2.2). This justification is a working of God alone, and is not merited by any works or deeds done by the justified (Ephesians 2.8-9).
Regeneration and Sanctification
At the moment of salvation, the sinner is given a new heart with new desires for the things of God. This too is an act of God, and is not motivated or inspired by human desires or works (Titus 3.5). This does not mean, however, that the sinner becomes to ally and perfectly righteous in his or her earthly life (Romans 7.15-17). Rather, God works in the heart and mind of the converted through his Spirit to bring about an ever-increasing level of righteousness in daily life (Romans 8.13). That is, the believer's slavery to sin is broken and his or her sinful tendencies and desires are progressively weakened through the power of the Spirit (Romans 6.20-22). This reality calls the believer to become an active participant in God's battle against sin in his or her life, and to rest assured in the eventual victory over it. While regeneration is an immediate reality in the believer's life, the process of sanctification is life-long and will continue unto death. But God will continually provide the believer with grace upon grace so that the believer can and will persevere through this battle with sin. In this sense, the process of sanctification is divine and human endeavor; the individual is empowered by God to fight sin and pursue holiness.
When a believer dies, he or she is made perfect and holy; the process of sanctification having been completed. The believer is taken to heaven to be with Christ and bask in his glory (Philippians 3.20-21).