To elect means to select or choose. According to the Bible, before creation God selected from the human race those whom he would redeem, justify, sanctify, and glorify in Jesus Christ. (Romans 8:28 - 39; Ephesians 1:3-14; 2 Thess. 2: 13, 14; 2 Timothy 1: 9, 10) The divine choice is an expression of free and sovereign grace. It is not merited by anything in those who are chosen. God owes sinners no mercy of any kind, only condemnation; so it is a wonder that he should choose to save any of us.
Like every truth about GOD the doctrine of the election involves mystery, and it sometimes stirs controversy. but in Scripture it is a pastoral doctrine, helping Christians to seeing how great is the grace that saves them, and moving them to respond with humility, confidence, and praise. We do not know what others God has chosen among those who do not yet believe, nor why he shows us in particular. We do know that we believe now only because we were chosen, and we know that as believers we can rely on God to finish the good work he has begun. (1 Cor. 1: 8, 9 Phil. 1: 6; 1 Thess. 5: 23, 24; 2 Tim. 1:12; 4:18) For these reasons the knowledge of the election is a source of gratitude and confidence.
Peter tells us we should be "diligent to make our call and election sure" (2 Pet 1:10)- that is, certain to us. Election isknown by its fruits. Paul knew that the Thessalonians had been chosen because he saw their faith, hope, and love, the transformation of their lives brought about by the gospel. 1 Thess. 1: 3-6
Reprobation is the name given to God's eternal decisions regarding those sinners whom HE has not chosen for life. In not choosing them for life, God has determined not to change them. They will continue in sin, and finally will be judged for what they have done. In some cases God may further remove the restraining influences that keep a person from extremes of disobedience. This abandonment, called hardening, is itself a penalty for sins. Romans 9:18; 11:25; Ps. 81:12; Romans 1:24, 26, 28.
Reprobation is taught in the Bible, but as a doctrine its bearing on Christian behavior is indirect. God's decree of election is secret; which persons are elected and which are reprobate will not be revealed before the Judgment. Until that time, God's command is that the call to repent and an believe be preached to everyone.