In a time and culture in which love has come to mean any fuzzily defined positive feeling, John’s healthy focus on the truth is a welcome change. There is such a thing as truth and we find it in Jesus. There are also swindlers who have gone out into the world, who deny some basic doctrines about Christ. John calls them deceivers and antichrists.
We don’t have to look very hard in the Bible to find warnings about spiritual deception. Several of them come out of the mouth of Jesus. For example, Matthew 24:11,“Then many false prophets will rise up and deceive many.”