The letter known as 1 John was sent to a group of believers who were in the midst of an unsettling situation. Some of them had abandoned faith in Jesus the Messiah as it had first been taught to them. They found the proclamation that God had come in a human body impossible to reconcile with the common Greek idea that the flesh is evil and only spirit is good. But despite their denial of the Messiah, their immoral lives and their lack of practical love, they claimed to know God and belong to God. They asserted that their spiritual insight put them above the rest of the group, which they demonstrated by deserting the fellowship. Those left behind were deeply shaken, uncertain about everything they had been taught.
Someone who was close to this community and who had been an eyewitness of Jesus wrote to reassure them of what they had heard from the beginning. The author doesn’t identify himself, but very likely he was the apostle John. Much of the language is similar to the Gospel of John. The letter testifies to the reality of the Messiah’s coming in the flesh, reassuring the believers that they have full access to the truth. It emphasizes godly living and practical caring as the signs of those who genuinely know God.