About 50 C.E., on his second missionary tour, Paul visited Corinth for the first time. During his 18-month stay, he helped establish the Christian congregation in that city. At the time, Corinth was a wealthy maritime crossroads with a sizable population. Like many other large port cities, Corinth was known for its moral decadence.

 After the congregation in Corinth was established, Paul wrote a letter to them, a letter that no longer exists. (1Co 5:9) Later, during his third missionary tour, Paul heard disturbing reports about the congregation in Corinth. (1Co 1:11; 5:1; 11:18) He also received a letter of inquiry from the congregation. (1Co 7:1) Then, about the year 55 C.E. while in Ephesus, he wrote this inspired letter, now known as 1 Corinthians. (1Co 16:8) Among other things, he encouraged the Christians in Corinth to reject false teachings, to remain united, to shun immorality, and to strengthen their faith in the resurrection.

 From the contents of 1 Corinthians, it is clear that Paul knew his audience and their circumstances. He drew illustrations from such things as the custom of having guardians to take care of children and the Greek athletic games. (1Co 4:15; 9:24-27) His comments reveal knowledge of the local religious and moral climate as well as the philosophical ideas that were popular in Corinth.​—1Co 1:20; 6:9, 10; 15:12.

 In this letter, Paul quotes many times from the Hebrew Scriptures, thereby shedding light on their meaning.​—1Co 1:19, 31; 2:9; 3:19; 9:9; 10:7; 14:21; 15:45, 54.

 The authenticity of 1 Corinthians and also of 2 Corinthians is unquestionable. These letters were ascribed to Paul and accepted as canonical by the early Christians, who included them in their collections. Additionally, it is said that 1 Corinthians is alluded to and quoted from in a letter called First Clement, written from Rome to the Corinthians and dated about 95 C.E. Such writers as Ignatius of Antioch, Polycarp, Justin Martyr, Athenagoras, Irenaeus, and Tertullian also quoted from or referred to 1 Corinthians.