You can’t talk publicly about Christianity unless at some point you get down to say, “Well, what is it?” There’s great consensus that 1 Corinthians was written just 20 years after the death of Jesus Christ. So when Paul says he’s summarizing the message the Corinthians heard and believed before this, he’s talking about something that happened a handful of years after Jesus’ death. If you want to get down to the irreducible core of what Christianity is about, here it is in this passage. This is the gospel. The gospel is about 1) Jesus, 2) sin and substitution,
