What did Paul accomplish during his time with the Corinthians?

Paul was with the Corinthians long enough to lay out all the biblical principles of morality and spirituality. Although he was not with them long, his ministry, sustained by the miraculous working power of God, helped Christianity get off the ground and survive among people steeped in idolatry and Judaism.

Les explains that Paul was with the Corinthians long enough to lay out all the biblical principles of morality and spirituality. He notes that Paul was not in any one place very long, but if it had not been for the miraculous working power of God, Christianity would never have gotten off the ground. The odds were impossible because the people were steeped in idolatry, except the Jewish element, and they were just as steeped in their Judaism. Yet through God's miraculous working, it survived, even though Paul's stays were brief.

1 Corinthians 6:15

Know ye not that your bodies are the members of Christ? shall I then take the members of Christ, and make them the members of an harlot? God forbid.

Was Paul with the Corinthians long enough to teach them all these biblical principles?

Yes. Paul was with them long enough to lay out all these biblical principles of morality and spirituality, even though he was not with them long. He was not in any one place that long, and Christianity survived impossible odds only by God's miraculous working power.