What is the difference between the Gospel of John and 1 John?

It is traditional to believe that 1 John was written by the author of John's Gospel, so the first thing to recognise is that both 1 John and John's Gospel were originally anonymous and only attributed to the disciple John later in the second century. Scholars say that the Gospel could not have been written by an eyewitness to the events it portrays, thus ruling out John or any other disciple as its author. In fact, a careful analysis of John's Gospel shows that it was actually inspired by Luke's Gospel.

1 John and John's Gospel were certainly written in the same community, known today as the Johannine community because of the traditional association with John, and 1 John shows evidence of a split in the community.

Some scholars say that 1 John was written in 3 stratas and by various authors, and that this process was completed before the Gospel of John. The first strata was from a Jewish, pre-Christian sect; the second strata made reference to Jesus as the Son of God; the third strata saw him as "coming in the flesh" for propitiation of sins and as "the Christ". An important difference compared to John's Gospel is that the author of the Johannine epistles never referred to Jesus as the"Word", other than in the single instance of the disputed verse, 1 John 5:7. This verse is not found in the earliest manuscripts of this epistle and is widely regarded as a fourth century insertion.

Whether 1 John had a single author, a team of authors or was written over time, with the last stage being completed early in the second century, we do not know who the author or authors were.

AnswerThe Apostle John was the writer of 1, 2, and 3 John as well as the Gospel of John.