One of the doctrines of classical dispensationalism that I find most bizarre is its teaching that the Old Testament is a system of works righteousness, that is, the belief that Old Testament believers attained right standing with God by obedience to the Mosaic Law. Some, such as John Hagee, even teach that modern Jews are saved by that means. I understand that modern dispensationalists have generally repudiated that doctrine.
However, I see a very different teaching in the Old Testament.
Look, example, at Isaiah 26:12: "O LORD, You will ordain peace for us, for You have indeed done for us all our works." The prophet testifies that our good works have actually been done in us by God! And again in Isaiah 46:13: "I bring near My righteousness, it is not far off; and My salvation will not delay." Consider also Isaiah 52:1: "Awake, awake, put on your strength, O Zion; put on your beautiful garments, O Jerusalem, the holy city; for there shall no more come into you the uncircumcised and the unclean." This is the same imagery used in Zechariah 3:3-4, in which the High Priest Joshua is first seen in the filthy garments of his own unrighteousness (cp. Isaiah 64:6), to be clothed anew in Christ's righteousness: "'Remove the filthy garments from him.' And to him he said, 'Behold, I
have taken your iniquity away from you, and I will clothe you with pure
vestments.'" This imagery is picked up by the Apostle John in the Revelation, such as Rev. 3:18 and 7:14.
The Prophet Jeremiah even uses Christ as our righteousness as His name! Jeremiah 23:6 tells us of the Branch of David, "In his days Judah will be saved, and Israel will dwell securely. And this is the name by which he will be called: ‘The Lord is our righteousness.’" The prophet tells Israel that their righteousness is not by their own actions, but rather to be found in their Messiah to come!
It can be fairly said that these prophets are obscure, compared to the clarity of the Gospel in the New Testament. Of course that is so. The Old Testament contains the Gospel under types and shadows, both of which are removed in the New Testament. The glory of the person and work of Christ far exceed that of their obscurity in the Old Testament, just as the smell of baking bread, as wonderful as it is, is far exceeded by the taste of the bread, dripping with melted butter! But the fact that the New Testament glory is greater should never be allowed to deny the presence of the Gospel in the Old Testament.
And, on a side note, I think it is crucial to mention that these truths are what we need to be showing our Jewish neighbors, in the hope that we may see the day when God will remove the veil from their eyes, and they will come in repentance to the Messiah that they initially rejected (Romans 11:25-27).