The Old Testament speaks of Jesus. Luke 24 says so. However, like the disciples, we are often slow of heart to believe all that the prophets have spoken, all that the law foreshadowed, and all that the Psalms have sung about Lord Jesus. Of course, Jesus is not calling us to trample texts underfoot in order to make them say what they don’t say, but neither is He calling us to read the Old Testament as if he could only be re-imagined in it by disciples who are now motivated to prove their Messianic point. Jesus is in the Old Testament text because the Holy Spirit intended Him to be there. Jesus is there by virtue of inspiration.
So, how do we see Him? One method is to keep Biblical theology ever before the mind’s eye. Biblical theology is the historical unfolding of the plan of redemption. Unlike systematic theology, which uses logic to order the collated information of Scripture under loci, Biblical theology’s organizing principle is history. Now, when we think of the historical development of Scripture, we use the theme of covenant. God was unfolding the Covenant of Grace in history like a flower, through different covenantal administrations.
However, even more basic is the two Adam Christology. In other words, we find the whole story of the Bible summed up in the two Adams, the Adam of Genesis 1-3 and Christ as the second Adam. The Bible speaks of both as federal heads. All are or have been united to the first Adam. But only those who have faith in Christ are united to Him as the second Adam (I Corinthians 15:45-47). This paradigm is historical. The first Adam represents all of humanity in the Covenant of works and Christ, the second Adam represents His people in the Covenant of Grace. It is important for the exegete to keep these covenants in mind when looking to see the Messiah in the Old Testament.
Let me give one example. Let’s take the two Adam Christology as our example. When God planted the Garden of Eden, he placed Adam in it to guard and tend its soil. Adam already owed a natural obedience to God by virtue of creation. However, God, through a special act of providence, entered the Covenant of Works with him (WSC 12). In this probationary covenant, Adam was to keep the prohibition to not eat from the Tree of the Knowledge of Good and Evil. If he ate, he would receive the penalty of death. However, if he obeyed, he would receive the promises of the covenant and enjoy eternal life. We are not told how long after being placed there that Eve, his wife, was approached by the serpent, but it was likely not long. In that moment, Adam was put to the test by Satan, and he failed. This failure was not only personal but corporate. In Adam all humanity was imputed with the curse of death.
Fast forward to the New Testament. In the Gospels we find Christ experiencing a similar temptation. Naturally, the details are different. The second Adam is in a desert and not a garden, he does not have the aid of a helpmeet, and he is hungry and thirsty after a forty day fast. But when Satan tempted Christ, he withstood the temptation. Now, this story is basic to a Christian’s understanding of salvation. But it’s also important for seeing Christ in the Old Testament. Let me give you an example.
Scripture gives two different accounts of Saul’s death. The first account (I Samuel 31) is to be taken as the true account. Saul asked his armor bearer to kill him, but the young man refused and so Saul took his own life. However, in the second account (II Samuel 1) we hear what David heard from the mouth of an Amalekite who claimed to have just returned from the Israelite camp. The Amalekite told David and his men that he was responsible for killing Saul, at the king’s request, and that is how he came into possession of the royal crown and the armband.
Let’s think together about the details. First, it is striking that this young man is an Amalekite. Why? Because it was through Saul’s disobedience to God regarding the Amalekites that he was rejected as king (I Samuel 15:23). And now, it was an Amalekite that came to David and tempted him to take the royal crown (II Samuel 1:10). It is hard not to see an analogy between the first and second Adam as they were both tempted by Satan. What is more, just as David was tempted to take the kingdom so too was Christ in his temptation (Luke 4:5). Both refused the offer. Strikingly, we are never told that David took the crown from the Amalekite. Instead, in second Samuel chapter two we are told that men from Judah came to where David lived in Hebron and anointed him as king. David did not seize the kingship. He did not succumb to the Amalekite’s temptation. Thus, Saul is the mirror image of Adam in his failure and David is a mirror image of Christ in his victory, at least at this point. That is one way to see Christ in the Old Testament.
 Systematic theology is indispensable to the preacher. However, in this article I will confine my comments to Biblical theology.
The Covenant of Preservation or the Noahic Covenant was the first, which was followed by the Abrahamic Covenant and the Mosaic Covenant and the Davidic Covenant all culminating in the New Covenant.