Get this: Paul never actually met Jesus while he was alive. But that didn't stop him from becoming the numero uno authority on his life and death. Go figure.
Paul's Jesus is pretty different than the Jesus we see in the four gospels. For starters, both letters to the Corinthians were written nearly 20 years before the gospels were ever spilled onto parchment. Paul doesn't tell many stories about Jesus's life; he doesn't quote anything he ever said; in fact, Paul doesn't seem very concerned with the living Jesus at all.
What's up with that?
Well, it's probably because the people he's writing to—the Corinthian Christians—would have already known all that jazz. Paul has already been to Corinth to lay the groundwork. He's already dazzled them with fancy stories about Jesus and his disciples, and the Corinthians totally loved it. Now, he's mostly focused on discussing what the life of Jesus means for Christians (source). He's taking it to the next level.
The one story Paul does tell about the life of Jesus is actually the oldest version of the Last Supper story that we get in the Bible:
For I received from the Lord what I also handed on to you, that the Lord Jesus on the night when he was betrayed took a loaf of bread, and when he had given thanks, he broke it and said, "This is my body that is for you. Do this in remembrance of me." In the same way he took the cup also, after supper, saying, "This cup is the new covenant in my blood. Do this, as often as you drink it, in remembrance of me." (1 Corinthians 11:23-25)
It's not 100% clear how he this information was "received from the Lord," since Paul wasn't present at the event and never met Jesus during his lifetime. Of course, he may mean he received this information in a vision from God. If that's true, it was a pretty detailed vision. It's probably more likely that he heard it from other disciples of Jesus (like Peter or James). We're guessing they would have loved telling Paul about all the good times they had out in the road back in the old days.
Paul wasn't around to witnesses Jesus's death either, but he sees this event as easily the most important in Jesus's entire life. It makes Jesus who he is and reveals his true power and might. Sure, Jesus said a lot of nice things, but when push came to shove, he gave up his life out of devotion to God. That's so hardcore.
Of course, the flip side of Jesus's death is his resurrection. The whole thing would be a pretty big downer without the whole happy ending that God tacked on.
Paul believes that the resurrection of Jesus reveals the way God works in the world. He says that Jesus "was crucified in weakness, but lives by the power of God" (2 Corinthians 13.4). Translation: yeah, it might seem not-great to live your whole life as a peasant and then be abandoned, humiliated, and publicly executed for crimes against the Roman Empire, but that's just how God rolls. Our normal way of thinking about things (weakness: bad, power: good) is wrong. Remember, Paul says, "God chose what is weak in the world to shame the strong" (1 Corinthians 1:27). Bring on the shame, haters!
So what do all these things that Jesus did mean?
Well, Paul is pretty sure that the death and resurrection of Jesus have transformed the world. And anyone who believes will be changed, too. Christians are supposed to be living completely new lives as risen people. Paul says, "If anyone is in Christ, there is a new creation: everything old has passed away; see, everything has become new!" (2 Corinthians 5:17). Pretty snazzy.
That's why Paul doesn't say that Christians are just people who believe in Christ, they are "in Christ." This is actually one of his favorite sayings. Don't believe us?
See? Told you so.
Paul also believes pretty firmly in the second coming of Christ. Basically, this just means that he thinks that Jesus is going to make an encore appearance on earth. He'll judge the living and the dead and establish God's kingdom on earth. All in a day's work for the Savior of the world.
Like a lot of 1st-century Christians, Paul also thought that Jesus would be coming back pretty soon. Like any second now. Maybe he would even live to see it (fingers crossed). This also makes him pretty annoyed that other Christians just can't hang on for one more day and concentrate on not sinning.
Paul's timing was slightly off. Like by at least 2,000 years. But, hey—Jesus does work off his own watch.
Overall, Paul is pretty concerned about keeping the focus on Jesus. He's really clear that his thoughts aren't his own—they're God's. And he resists talking about himself as much as possible. Anytime anything good happens, it's Jesus working through him. Heck, anytime anything bad happens it's Jesus. Stonings? Imprisonment? Starvation? Thorns in sides? That's all Jesus working to make Paul stronger through weakness. Thanks?
Paul wants people to follow his lead, but he's also cautious about making sure they don't confuse him with Jesus. He rebukes the Corinthians for worrying too much about which apostle to follow: "Was Paul crucified for you? Or were you baptized in the name of Paul?" (1 Corinthians 1:13). Nope. He certainly was not.
Though it's also fair to say that Paul has shaped our modern picture of Jesus through his letters. He tells us that everything he writes is from God, but is that just supposed to be the end of the story? Paul is the first biblical author to really interpret what Jesus means and those interpretations have stuck.
Hey, 2,000-year-old theological assertions die hard.