Before embarking on a discussion of The First Epistle of John, it is useful to first consider the very foundations of human thought.
The scientific method is a methodology one (supposedly) uses in pursuit of scientific truth. The elements are known to most of us:
1) Hypothesis--Offer a concept or idea of how data might best be interpreted. For example, why do the sun, moon, stars and planets move around the earth as they do, with the planets exhibiting "retrograde motion," that is, appearing to move backward in the sky?
2) Test against data. In science, the data is "future" data. That is, a testable / repeatable experiment is performed, and from which data can be derrived. For example, the planet Jupiter will keep moving, and therefore, one can test the competing theories of Ptolomy and Copernicus to predict the future position of the Jupiter.
3) The theory that answers the most data is preferred; and
4) The theory that is the simplest and most elegant is preferred over ugly and combersome theories.
Elements 3 and 4 do not always line up. For example, Ptolmey's explanation of retrograde motion (why planets appear to move backwards relative to the stars) at certain seasons was that the sun, moon, stars, and planets rotated on spheres controlled by various "epicycles." (Picture a child's gyroscope within a second gyroscope, within another gyroscope, to about 45 or so levels, each gyroscope driven by a complex movement of gears like a swiss watch. Though neither of these pictures exacly describes an "epicycle" of Ptolomy, they are as close as we will come here.)
Copernicus offered an alternative hypothesis, that the larger a mass was, the more stationary it was, and that therefore, with little measurable error, the earth rotated around the sun, and revolved on an axis.
Amazingly, it was not until the time of roughly Abraham Lincoln that measurements were exact enough that the Copernican theory could better predict data . . . where the planets would be found. Nevertheless, because it was so much simpler and more elegant than the Ptolemiac theory, it had become the favored theory centuries before Abraham Lincon's time.
The dominance of the Copernican theory prior to experimental superiority therefore highlights the importance of the simplicity or elegance of a theory. If a theory becomes unwieldly, complex or convoluted, it must give way to a simpler and more elegant theory.