And a great and a terrible gulf divideth them; yea, even the word of the justice of the Eternal God, and the Messiah who is the Lamb of God, of whom the Holy Ghost beareth record, from the beginning of the world until this time, and from this time henceforth and forever.Several things came to my mind reading this. First of all, the verse in in D&C 130:8 that "past, present, and future, [...] are continually before the Lord" or in Alma's words: "all is as one day with God, and time only is measured unto men" (Alma 40:8). Eternity is a concept that is difficult to grasp for the mortal man, but it is different for the "Eternal God" who has past, present and future continually before Him. This language expresses his nature. He is "Alfa and Omega, the beginning and the end" (3 Nephi 9:18). He is also the great Jehovah, i.e. the great I AM. Of Him, the Holy Ghost bears record, as the cited scripture states.
Jacob 4:13
for the Spirit speaketh the truth and lieth not. Wherefore, it speaketh of things as they really are, and of things as they really will be; wherefore, these things are manifested unto us plainly, for the salvation of our souls. But behold, we are not witnesses alone in these things; for God also spake them unto prophets of old.D&C 93:24
And truth is knowledge of things as they are, and as they were, and as they are to comeAgain in 1 Nephi 10:19
For he that diligently seeketh shall find; and the mysteries of God shall be unfolded unto them, by the power of the Holy Ghost, as well in these times as in times of old, and as well in times of old as in times to come; wherefore, the course of the Lord is one eternal round.Moses 6:66-67
And he heard a voice out of heaven, saying: Thou art baptized with fire, and with the Holy Ghost. This is the record of the Father, and the Son, from henceforth and forever; And thou art after the order of him who was without beginning of days or end of years, from all eternity to all eternity.The pattern is quite clear. God is a "God of truth" (Ether 3:12) and is "from all eternity to all eternity". Hence, truth is also eternal. He invites us to learn these truths and sends messengers to teach us and the Holy Ghost to testify of it. In that way we may eventually take part in His eternal glory.