Election is in Christ unto salvation from eternal judgment. Christ is our deliverance from condemnation. Election is God the Father's choice to save sinners in Christ (Ephesians 1:4-6). Reprobation is the opposite of election. It is the reprobate's choice to reject God's salvation in Christ (John 3:18).
Election is in Christ alone by God's grace. He saves believers from the condemnation of our sin. God's grace is his goodness, leading us to repentance (Romans 2:4). The reprobate chooses to obstinately reject the goodness of God's grace in Christ.
Election is sure in Christ alone, and confirmed by your faith (2 Peter 1:1, 10); reprobation is confirmed through continual rejection of Christ. Election gives mercy to sinners through Christ crucified (Romans 5:8). Christ risen from the dead brings justification to sinners by faith alone (Romans 4:5; 10:9). The reprobate is hardened in his own sin that rejects Christ forever.
Election is in Christ alone, by God's active will to save all who believe (Acts 16:31). Reprobation is God's passive will to let others continue in their sin of unbelief (John 3:36). Election is the will of God in Christ (1 Peter 1:1-2). Reprobation is the will of man in sin (John 5:40).
Election is in Christ alone, to the praise of God's glory. God saves us by faith in Christ to the praise of His glorious grace (Ephesians 1:6). God passively allows those who are reprobate to reject Christ unto their own just condemnation (John 3:19).