I haven’t been able to read the Bible as most people do, seeing a new start at the New Testament. It’s my natural tendency to read and understand things in harmony, whenever possible. And in any case: the Old Testament contains information about people like Abel and Noah and probably Job and his friends who weren’t covered by the old covenant. How were they saved, by works or by faith? or were they damned, because they were neither Israelites nor post-Christ?
The covenant made with the Israelites was a separate and parallel covenant to the eternal covenant made by Christ in the Pascal sacrifice in his blood. The Israelite covenant made in the flesh Abraham and his house was eternal: “My covenant will be in your flesh for an everlasting covenant” (Gen. 17:13b). Has it been abrogated? Will we make the Lord into a liar? Will we say his ends failed to meet their goal?
No-one has ever been saved by works. Works are the fruit of faith—of trust in God (James 2:14-18 and the whole letter). This was the major point of contention between Jesus and the legalistic Jews of his time. Jesus followed the Mosaic Law completely: but not because he thought it was necessary to his salvation, but because he loved God with all his heart and all his soul and all his mind and all his strength, and because he trusted God. And a person who completely loves God keeps God’s commandments completely.
The legalistic Jews did not practice the Israelite religion, and did not fulfil the Law (Luke 18:9-14). They were carnally minded, following the rules not out of their love of God, but to look righteous to other people, and to let them feel superior to the lepers and the tax collectors and the Greeks.
The Israelites were given the true religion and a special bonus covenant: that they might protect the knowledge of God, that his Scripture might be written by them, that they might collectively, as a nation, be a prophecy and a sign of the incarnate Lord. But just like previous generations had found idols in foreign gods to worship, the self-proclaimed righteous Jews in Jesus’ time had found idols in the works of the law and a corrupted notion of righteousness to worship. The forgot the truth which permeated their Scripture.
The Law was not meant to be their ticket to heaven, despite the common Christian understanding. But it was a gift and a blessing to them, and sees to their salvation through the embodiment of Jesus Christ, the Lord’s salvation.
Now, do I say, a good Gentile Christian has to follow the Law which came to the Israelites?—do we follow the Mosaic Law? No. That Law hasn’t come to us: we are not part of that covenant. It was made with a specific nation. Paul’s letter to the Romans makes that clear.
No. But I shall approve to myself of what the Lord approves of, and condemn from myself the things which the Lord condemns. The whole Bible is my law, and I eagerly study it to know what the Lord wants me to know.
Still don’t believe me? Read the Book of Job, and tell me it isn’t a “covenant of grace through faith” document. Read the Acts of the Apostles, and tell me Paul doesn’t keep being Jewish after he becomes Christian.