Short answer: The most likely author of 1 Corinthians 1:4–5 is the Apostle Paul. Evangelical Christians affirm Paul as the historical, inspired author of 1 Corinthians and view his authorship as the basis for the letter’s apostolic authority.

Key points (evangelical perspective)

– Identity and credentials
– Paul (formerly Saul of Tarsus) — a Jew, trained as a Pharisee (Acts 22:3; Philippians 3:5), and a Roman citizen.
– He was converted on the Damascus road after a personal, bodily encounter with the risen Christ (Acts 9; 1 Cor. 15:8), and became an apostle called directly by the Lord.
– Evangelicals stress Paul’s apostolic authority because of that calling and his role as an eyewitness witness to the risen Jesus (1 Cor. 9:1; 15:3–8).

– When and where he wrote 1 Corinthians
– Most evangelicals date the letter to Paul’s third missionary journey, written from Ephesus (around AD 53–57, often c. AD 55).
– The letter addresses a congregation in Corinth where Paul had previously preached and established the church (Acts 18).

– Why Paul is credited as the author
– Internal evidence: the letter opens and closes with Paul identifying himself as its writer and as “called by the will of God” (1 Cor. 1:1; cf. the personal references and travel plans in 1 Cor. 16).
– External evidence: the earliest church fathers (e.g., Clement of Rome, Ignatius) quote or refer to Paul’s letters and attribute them to him.
– Linguistic, theological, and pastoral consistency with Paul’s other letters supports authenticity in evangelical scholarship.

– Paul’s background that shapes the letter
– His Jewish scholarly formation and missionary experience explain his concern for the gospel’s relation to Jewish law, for gospel-centered unity, and for wise pastoral care.
– His emphasis on God’s grace, human weakness, Christ crucified, spiritual gifts, and the resurrection is central to 1 Corinthians (1:4–2:5; chs. 12–14; ch. 15).

– How 1 Corinthians 1:4–5 fits Paul’s heart and theology
– 1 Cor. 1:4–5 (Paul’s thanksgiving) — Paul opens the letter by thanking God for the Corinthians’ enrichment in Christ, which reflects his pastoral gratitude and reassurance even while addressing serious problems (divisions, immorality, abuses of spiritual gifts).
– The verse shows Paul’s pastoral balance: he affirms God’s work in believers while calling them to greater faithfulness.

– Evangelical convictions about Scripture and Paul
– Evangelicals typically hold Paul’s epistles to be inspired Scripture and authoritative for doctrine and life.
– Paul’s teaching in 1 Corinthians is therefore treated as normative for the church, subject to proper interpretation in its historical context.

Suggested evangelical resources for deeper study
– Gordon D. Fee, The First Epistle to the Corinthians (NICNT) — detailed, evangelical-critical commentary.
– F. F. Bruce, 1 & 2 Corinthians (Tyndale Old Testament/NT Commentaries) — concise and readable.
– D. A. Carson, in various collected works and study notes — helpful theological perspective.
– An ESV/NIV study Bible for verse notes and historical background.

If you want, I can:
– Provide the exact wording of 1 Corinthians 1:4–5 in a particular translation,
– Give a short outline of 1 Corinthians showing where 1:4–5 fits, or
– Summarize Paul’s life with key Scripture references. Which would help you most?