The most cursory reading of the first Epistle of John is enough to
show us that it bears a very strong likeness to the Gospel of John. The
same themes are prominent in both. In the Gospel they are set forth,
mainly but not exclusively, in the Lord's own words, and as illustrated
in His life. In the Epistle they are still enforced, but the main point
now is that they are to be demonstrated in the lives of the children of
God. The Gospel shows us things that are
true in Him. But the Epistle speaks of "a new commandment . . . which thing is true in Him
and in you" (1 John 2: 8). This brief sentence furnishes us with a key to the whole epistle.
This epistle was amongst the last to be written. There were already
"antichrists" about, as the second chapter states. These men laid claim
to superior knowledge. They claimed that their teachings were a moving
forward, an improvement on what had gone before. But under pretence of
moving
forward they moved clean
away from the
foundation which had been laid in Christ, and from the life which from
the beginning had been manifested in Him, when He came amongst us in
flesh. Hence the first thing needful was to make very plain that there
had been a real, true, objective manifestation of the eternal life in
Christ.