“which He will manifest in His own time, He who is the blessed and only Potentate, the King of kings and Lord of lords, who alone has immortality, dwelling in unapproachable light, whom no man has seen or can see, to whom be honor and everlasting power. Amen” (1 Timothy 6:15-16).
Much like an earthly king, the word “Potentate” describes a royal minister of great authority (1) But unlike a human monarch, Jesus does not rule within a territorial border; instead, He is the “…King of kings and Lord of lords.” Similar designations for Jesus are found in the book of Revelation as well. Because of this, we can say that Jesus exercises ultimate authority over everyone and everything that has ever come into existence.
The following description from this passage (“…who alone has immortality) makes use of a familiar word (immortality) that may have lost some of its meaning.
For instance, we might introduce an outstanding athlete with the phrase, “The immortal…” By this, we mean that the athlete in question possesses skills that make that person seem more than mortal. However, the word “immortality” actually describes someone who is incapable of dying.
In the strictest sense, God is the only Being who is truly immortal, for He has always existed and has no end. Thus, God possesses inherent immortality and is eternally self-existent. This makes God different from angelic beings (who are created and thus have a beginning) or resurrected men and women of God (who are also created but have immortality conferred upon them). One author brings some additional clarity to the use of this word…
“Jesus Christ is God and, therefore, is the only one who has intrinsic immortality. However, He assumed human flesh, in order to die as man’s substitute for sin. ‘I am He that liveth, and was dead;’ He says; ‘and, behold I am alive for evermore’ (Revelation 1:18). Now He ‘hath abolished death, and hath brought life and immortality to light through the gospel’ (II Timothy 1:10). Now we can say, with Him: ‘This mortal must put on immortality’ (I Corinthians 15:53).” [2]
Another source closes with a helpful summary of this passage…
“The Second Coming of Christ will reveal the character of God. Notice, please: (1) He will be seen as the blessed and only Potentate (2) King of kings (3) Lord of lords (4) Who only hath immortality (5) dwells in an unapproachable light (6) whom no man hath seen, nor can see (7) to whom all honor and power are due.” (3)
(1) G1413 dynastes Thayer’s Greek Lexicon https://www.blueletterbible.org/lang/lexicon/lexicon.cfm?t=kjv&strongs=g1413
(2) Institute for Creation Research, New Defender’s Study Bible Notes [1 Timothy 6:16] https://www.icr.org/bible/1Timothy/6/16/
(3) Don De Welt, Paul’s Letters to Timothy and Titus, [Comment on 1 Timothy 6:15] College Press, Joplin, Missouri Copyright 1961 https://archive.org/stream/BibleStudyTextbookSeriesTimothyAndTitus/18TimothyAndTitus_djvu.txt