Most evangelicals identify the author of 2 Corinthians (including 2 Corinthians 5:19–20) as the apostle Paul. Here are key points about him and why evangelicals accept him as the author, plus how those verses fit his theology and ministry.

Who Paul was (evangelical summary)
– Born Saul of Tarsus, a Jew of the tribe of Benjamin, trained as a Pharisee under Gamaliel and a Roman citizen (Philippians 3:5; Acts 22:3; Acts 22:25–29).
– Initially persecuted the early church, but experienced a dramatic conversion on the road to Damascus when Christ appeared to him (Acts 9). From that point he was a missionary apostle, especially to the Gentiles.
– Traveled on several missionary journeys, planted churches across Asia Minor and Greece, and wrote many New Testament letters. Tradition and early church testimony place his martyrdom in Rome under Nero in the 60s AD.
– Evangelicals emphasize that Paul’s apostleship was authoritative because it was by Christ’s call (Galatians 1:1) and that his letters are inspired Scripture (2 Timothy 3:16).

Why Paul is the most-likely author of 2 Corinthians
– The letter itself names Paul as its writer (2 Corinthians 1:1) and reflects his distinctive vocabulary, theology, personal tone, and situation (defending his apostolic ministry, addressing conflicts in the Corinthian church).
– Both evangelical scholars and most mainstream historians date 2 Corinthians to the mid-50s AD (during or shortly after Paul’s third missionary journey), and place its composition from Macedonia.
– While some critical scholars have discussed the letter’s compositional complexity (e.g., possible multiple fragments), evangelicals generally accept its core as Paul’s writing to the Corinthian church, preserving his authentic voice and concerns.

How 2 Corinthians 5:19–20 fits Paul’s theology and ministry
– The verses express central Pauline themes: God’s initiative in salvation, the atoning work of Christ, reconciliation, and the believer’s role in mission. In many translations they read roughly: “God was reconciling the world to himself in Christ, not counting men’s sins against them. And he has committed to us the message of reconciliation. We are therefore Christ’s ambassadors, as though God were making his appeal through us.”
– “Reconciliation” and “not counting sins” reflect Paul’s teaching on justification by faith and the forgiveness achieved in Christ (see Romans, Galatians).
– The image of believers as “ambassadors” (or “we are Christ’s representatives”) underlines Paul’s missionary urgency: Christians are entrusted with proclaiming God’s reconciliation to others.
– These verses summarize Paul’s gospel-centered ministry: God acts in Christ to reconcile sinners, and Christians participate in that mission.

Pastoral and evangelical implications
– Salvation is initiated by God, accomplished in Christ, and received by faith—foundational to evangelical doctrine.
– The church’s calling is evangelistic and reconciling: to proclaim the gospel and live as representatives of Christ’s reconciling work.
– Personal transformation (Paul’s “new creation” theme in 2 Corinthians 5:17) is evidence of God’s reconciling power.

For further study (evangelical resources)
– Commentaries: Gordon D. Fee’s commentary on 2 Corinthians (NICNT), and D. A. Carson.
– Biographical/introductory works: F. F. Bruce, “Paul: Apostle of the Heart Set Free”; N. T. Wright’s Paul volumes (for a broader scholarly-evangelical perspective).

If you’d like, I can: (a) quote 2 Corinthians 5:19–20 in a specific translation, (b) summarize scholarly dating and setting in more detail, or (c) show how these verses are used in evangelical preaching and practice.