About John's first letter
John, who wrote this letter, was the apostle John. He also wrote the Gospel of John and the letters called 2 John and 3 John.
These three letters have ideas very like those that John wrote about in his Gospel. John uses the same kinds of words in each place. The Gospel and these letters all speak about God's love and the light that God gives. John's Gospel tells people about Jesus, and his life. It tells people how Jesus is the way to know God. John shows that Jesus is the Son of God. He wanted people to know that Jesus had died to save them. But he wrote these letters to help people who already believe in Jesus. He tells believers how God wants them to live. He also wrote this letter to speak against the message of false teachers that some Christians had heard.