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

1 Corinthians 4:7 asks, 'For who maketh thee to differ from another?' The believer differs from the unbeliever because he has been born again by the Spirit of God, made a new creation in Christ. This difference is not due to any inherent quality in the believer but is solely attributed to God's sovereign grace. This is clearly affirmed in Scriptures such as Ephesians 2, which states that we are saved by grace through faith, underscoring that salvation is an act of God, not of man, thus granting all glory to Him.