No church in the New Testament is more like our modern churches than the Corinthian church.
John concludes his letter saying believers can have confidence about three things: 1) that you have eternal life, 2) that your sin cannot jeopardize that life and 3) that this gospel message is true.
John tells us genuine believers will confess that Jesus is the Christ — the Jesus who was confirmed by three witnesses: “water”, “blood” and “the Spirit.”
In Paul’s time Corinth was the 2nd most important city in the Roman empire. Corinth was an exceptionally wealthy and important city in Greece.
In 1 John 4:7-19, John explains why self-sacrificing love is a mark of a believer: this other-focused love is part of God’s holy character and God is in the process of giving us His character.