Matthew Brown notes that one fundamental teaching of The Church of Jesus Christ of Latter-day Saints is that the Savior’s gospel has been on the earth “from the beginning” (D&C 20:21-26; cf Moses 5:58-59; JST John 1:1). This is in accordance with 1 Nephi 10:18 where we find that God “is the same yesterday, today, and forever; and the way is prepared for all men from the foundation of the world, if it so be that they repent and come unto him.”
Some Christian leaders who lived shortly after the apostolic age declared the same truth. Eusebius, who served as bishop of Caesarea in A.D. 339, said that “it is obvious that [the biblical patriarchs] knew God’s Christ Himself, since He appeared to Abraham, instructed Isaac, spoke to [Jacob], and conversed freely with Moses and the prophets who came later… . Obviously we must regard the religion proclaimed in recent years to all nations through Christ’s teaching as none other than the first, most ancient, and most primitive of all religions, discovered by Abraham and his followers.” Many of the early Christian writers such as Tatian (ca. A.D. 150), Justin Martyr (A.D. 165), Tertullian (ca. A.D. 200), Irenaeus (ca. A.D. 115-202), Clement of Alexandria (ca. A.D. 160-215), Theophilus of Antioch (ca. A.D. 100-200), and Origen (ca. A.D. 185-251) also taught that Jesus Christ was the divine being who appeared unto mortals in the Old Testament. Therefore, Christianity was “not a new religion” but was “connected with the birth of mankind.” [Matthew B. Brown, All Things Restored: Confirming the Authenticity of LDS Beliefs, pp. 1-2]
“He is the Same Yesterday Today and Forever”
In 1 Nephi 10:18 we find: “[God] is the same yesterday, today, and forever; and the way is prepared for all men from the foundation of the world, if it so be that they repent and come unto him.” According to Camille Fronk, any serious study of the scriptures elicits queries related to the nature of the Lord’s Church before the dispensation of the meridian of time. While such language as baptism unto repentance, faith in the Lord Jesus Christ, and the gift of the Holy Ghost is abundant in the New Testament record, such familiar terms are conspicuously absent in the Old Testament account. Are we then to conclude that these fundamental principles and ordinances of the gospel were not understood and practiced before the coming of Jesus Christ? Numerous LDS scriptural sources and words of modern prophets suggest that the answer is “no.” God is the same yesterday, today, and forever (see D&C 20:12; Hebrews 13:8) and so are the saving principles and ordinances of the gospel.
Joseph Smith taught that the early inhabitants of this earth were as aware of the plan of salvation as those who have been instructed since the time of his coming. “We cannot believe that the ancients in all ages were so ignorant of the system of heaven as many suppose, since all that were ever saved, were saved through the power of this great plan of redemption, as much before the coming of Christ as since; if not, God has had different plans in operation … to bring men back to dwell with Himself; and this we cannot believe, since there has been no change in the constitution of man since he fell.”
Those prophets who succeeded Adam knew the same gospel and ordinances. “How could Abel offer a sacrifice and look forward with faith on the Son of God for a remission of his sins, and not understand the Gospel?,” the Prophet Joseph asked. “If Abel was taught of the coming of the Son of God, was he not taught also of His ordinances? We all admit that the Gospel has ordinances, and if so, had it not always ordinances, and were not its ordinances always the same?” [Camille Fronk, “The Everlasting Gospel: A Comparison of Dispensations” in Voices of Old Testament Prophets: The 26th Annual Sidney B. Sperry Symposium, pp. 171-175]