As the faith spreads it finds new converts among the Greek gentile population. But these new converts bring new and complex problems and the solution of these problems falls squarely on the back of one man, The Apostle Paul.
Sources:
http://preachingsource.com/journal/the-historical-background-of-first-corinthians/
https://zondervanacademic.com/blog/what-was-the-city-and-church-of-corinth-like-an-excerpt-from-ralph-martins-2-corinthians-wbc