What does the Bible say about who makes a believer differ from an unbeliever?

In 1 Corinthians 4:7, the Apostle Paul poses the question, 'For who maketh thee to differ from another?' This fundamental question highlights that the distinction between believers and unbelievers does not lie in human merit or decision but in God's sovereign grace. The believer has been born again by the Spirit of God and made a new creature in Christ, fundamentally differing in motives, goals, and reasons for living. It emphasizes that the credit for this difference goes solely to God, who saves and calls according to His own purpose and grace, as seen in 2 Timothy 1:9.