1 John 5.19 says in the original: "and the world whole in the wicked is lying." The Kingdom Interlinear Translation adds (one) to that like this: "and the world whole in the wicked (one) is lying." The "(one)" is not explicit but is implied. The NWT refines that literal reading for modern readers this way: "the whole world is lying in the power of the wicked one." Can you blame the translators for that?
I have to disagree with you here. In fact this is good example of translators reading their own pre conceived ideas into the text. It may seem 'obvious'to us that the authors are trying to convey dangers that contempories had no conception of, and Satan is the classic example of this.
There is no mention of satan in the hebrew bible until Job, here only the title ha-satan is used, 'the adversary', a noun description of a verb, it's a job title bestowed on a being rarther than the name of one.
This is what essentially is conveyed in the OT regarding Satan, part of the heavenly host - a fellow olympian of Yahweh looking down with scorn on the puny cares of man.Some obedient humans and angels are also called satan /adverary such as David 1 Samuel 24.
The new testement takes it's cue from secondtemple religious dualism in Babylon and early Zoroastrainism. The development of Satan as a "deceiver" has parallels with the evil spirit in Zoroastrianism, known as the Lie, who directs forces of darkness.
This in wikipaedia:
Rabbinical Judaism
In Judaism, Satan is a term used since its earliest biblical contexts to refer to a human opponent.[26] Occasionally, the term has been used to suggest evil influence opposing human beings, as in the Jewish exegesis of the Yetzer hara ("evil inclination" Genesis 6:5). Micaiah's "lying spirit" in 1 Kings 22:22 is sometimes related. Thus, Satan is personified as a character in three different places of the Tenakh, serving as an accuser (Zechariah 3:1β2), a seducer (1 Chronicles 21:1), or as a heavenly persecutor who is "among the sons of God" (Job 2:1). In any case, Satan is always subordinate to the power of God, having a role in the divine plan. Satan is rarely mentioned in Tannaiticliterature, but is found in Babylonianaggadah.[20]
In medieval Judaism, the Rabbis rejected these Enochic literary works into the Biblical canon, making every attempt to root them out.[19] Traditionalists and philosophers in medieval Judaism adhered to rational theology, rejecting any belief in rebel or fallen angels, and viewing evil as abstract.[27] TheYetzer hara ("evil inclination" Genesis 6:5) is a more common motif for evil in rabbinical texts. Rabbinical scholarship on the Book of Job generally follows the Talmud and Maimonides as identifying the "Adversary" in the prologue of Job as a metaphor.[2]