Even after God proved Jesus to be the promised “Lord and Christ,” false Christs were abundant. Jesus predicted,
For many will come in My name, saying, “I am the Christ,” and they will lead many astray (Matthew 24:5).
Other false teachers would take a more subtle approach. They would claim to represent Jesus, but a different Jesus, one of their own making. In 1 Corinthians, Paul was dealing with divisions caused by spiritual immaturity (1 Corinthians 3:1-4). In 2 Corinthians, the threat was more sinister. False apostles had arrived in Corinth. They worked to divide the Christians from their father in the faith, Paul. They claimed to know a better “Jesus” and a better “gospel” than Paul preached.
“Someone comes and proclaims another Jesus.”
For if someone comes and proclaims another Jesus than the one we proclaimed, or if you receive a different spirit from the one you received, or if you accept a different gospel from the one you accepted, you put up with it readily enough (2 Corinthians 11:4).