Paul begins his letter to the Corinthians by identifying himself and a person well known by the Corinthians as being the senders of the letter. He writes, “Paul, called by the will of God to be an apostle of Christ Jesus, and our brother Sosthenes.” Paul needs to address some pretty serious issues in the church at Corinth that will be difficult for some to receive so he identifies himself as a God-appointed apostle of Jesus. This “Functions to bolster his standing in a community where at least some were questioning his authority.”[1] Paul identifies himself as an apostle of Jesus in all except four of his epistles. The stress in this title seems to rest primarily on the source of his calling, not on his position. It was not his own choosing. Later in the book, he tells his readers “By the grace of God, I am what I am.” It was the conviction of his calling by God that gave Paul such boldness and confidence throughout his ministry as is readily seen in his writings. He can therefore address the issues because of his calling. In verse two he reminds the readers of their “calling” to be holy people.
We don’t know much about this “Sosthenes” but there was such a man in Acts 18:17. He was a ruler of the Corinthian synagogue and was taken and beaten by the Jews while the Roman Prefect of the province, Gallio, did nothing to stop it. It seems that he was a Jew who was very possibly beaten because he became a Christian. “We cannot be certain that the Sosthenes who joined Paul in writing to Corinth had earlier been a leading Corinthian Jew, but it is at least possible, and perhaps more than possible. There is no doubt that Paul is the senior partner; or that Sosthenes genuinely is a partner.”[2] Some suggest that Sosthenes was Paul’s amanuensis or secretary and did the actual writing of the letter. This too is possible because he’s not mentioned in the letter again. But regardless of his role Sosthenes is referred to as “our brother.” Thus the readers in Corinth must have been familiar with Sosthenes and this added credibility to Paul’s letter.
In several of the epistles, the addressees are referred to as “brothers.” Some of the modern translations change that to read “brothers and sisters” because the term is general and includes both just as the term “mankind” includes both genders. We see this also frequently in the book of Acts. By the time of Paul’s letter, it was already a common practice to call each other brother and sister. This practice led the pagan world around them to accuse the Christians of incest. The early church was also accused of cannibalism because they partook of “the body and blood of Jesus” during the solemn assemblies. Both of course were ridiculous charges. When Jesus was told that his mother and brothers were looking for Him, he replied, “Who are My mother and My brothers? […] Whoever does the will of God, he is My brother and sister and mother” (Mark 3:32-35). It’s not the physical relationship that Jesus refers to but the spiritual connection they have through their common faith in Jesus. Romans 8:14-16 explains: “For all who are led by the Spirit of God are sons of God. For you did not receive the spirit of slavery to fall back into fear, but you have received the Spirit of adoption as sons, by whom we cry, Abba! Father! The Spirit Himself bears witness with our spirit that we are children of God.” The same chapter says: “And we know that for those who love God all things work together for good, for those who are called according to His purpose. For those whom He foreknew He also predestined to be conformed to the image of His Son, in order that He might be the firstborn among many brothers” (Romans 8:28-29). Jesus Christ is the only Son of God. But God adopts humans into His family so that they all become spiritual brothers and sisters.
[1] Ciampa, Roy E., and Brian S. Rosner. 2010. The First Letter to the Corinthians. The Pillar New Testament Commentary. Grand Rapids, MI; Cambridge, U.K.: William B. Eerdmans Publishing Company.
[2] Barrett, C. K. 1968. The First Epistle to the Corinthians. Black’s New Testament Commentary. London: Continuum.