1st Corinthians 10:1 Moreover, brethren, I would not that ye should be ignorant, how that all our fathers were under the cloud, and all passed through the sea; 2 And were all baptized unto Moses in the cloud and in the sea; 3 And did all eat the same spiritual meat; 4 And did all drink the same spiritual drink: for they drank of that spiritual Rock that followed them: and that Rock was Christ.
[Patriarchs & Prophets pp 366>367] Adam, Noah, Abraham, Isaac, Jacob, and Moses understood the gospel. They looked for salvation through man's Substitute and Surety. These holy men of old held communion with the Savior who was to come to our world in human flesh; and some of them talked with Christ and heavenly angels face to face. Christ was not only the leader of the Hebrews in the wilderness—the Angel in whom was the name of Jehovah, and who, veiled in the cloudy pillar, went before the host—but it was He who gave the law to Israel. Amid the awful glory of Sinai, Christ declared in the hearing of all the people the ten precepts of His Father's law.
It was He who gave to Moses the law engraved upon the tables of stone. It was Christ that spoke to His people through the prophets. The apostle Peter, writing to the Christian church, says that the prophets “prophesied of the grace that should come unto you: searching what, or what manner of time the Spirit of Christ which was in them did signify, when it testified beforehand the sufferings of Christ and the glory that should follow.” 1 Peter 1:10, 11. It is the voice of Christ that speaks to us through the Old Testament. “The testimony of Jesus is the spirit of prophecy.” Revelation 19:10.
In His teachings while personally among men Jesus directed the minds of the people to the Old Testament. He said to the Jews, “Ye search the Scriptures, because ye think that in them ye have eternal life; and these are they which bear witness of Me.” John 5:39. At this time the books of the Old Testament were the only part of the Bible in existence. Again the Son of God declared, “They have Moses and the prophets; let them hear them.” And He added, “If they hear not Moses and the prophets, neither will they be persuaded, though one rose from the dead.” Luke 16:29, 31.
2nd Peter 1:19 We have also a more sure word of prophecy; whereunto ye do well that ye take heed, as unto a light that shineth in a dark place, until the day dawn, and the day star arise in your hearts: 20 Knowing this first, that no prophecy of the scripture is of any private interpretation. 21 For the prophecy came not in old time by the will of man: but holy men of God spake as they were moved by the Holy Ghost.
May The Lord add His blessing to the study of His word. God bless!