More proof in the puding.
The Gospel According to the Gospel advocates that God gave His covenant of righteousness to His friend Abraham and his descendants. That is God has imputed to Abraham and his descendents the same righteousness by faith that we New Testament believers have in Christ.
I know this flies in the face of what is taught in most Christian circles but this teaching is found in our New Testament. We simply have ignored it for another gospel.
We assume in our church gospel that the Old Testament saint’s had to work the Law for righteousness and that only we New Testament saints get all the grace and imputed righteousness. But this is not true. Abraham and his descendants too were imputed the same righteousness as we have to us today.
You can find more on this at “Abraham” if you wish to look at more scripture concerning this topic.
Now more proof in the pudding. Paul not only teaches the above mentioned, he also teaches that the Jewish nation sought to establish their own righteousness through the Law. To this we all say, I know. But Paul doesn’t stop there. He says they did this because they rejected God’s righteousness.
Since they did not know the righteousness that comes from God and sought to establish their own, they did not submit to God’s righteousness.
This righteousness was the imputing of righteousness that was received by Abraham for him and his decendants. The seal of this imputed righteousness was circumcision. The Jewish nation rejected the righteousness that circumcision was the seal of and instead wanted to establish their own righteousness through the law. They stumbled over the stumbling stone.
Why not? Because they pursued it not by faith but as if it were by works. They stumbled over the “stumbling stone.”
What the Jewish nation did was to reject what was offered to them by God which was testified to by circumcision. You can not reject what is not offered. And again Paul says they did not pursue their righteousness by faith. They unlike there father Abraham simple didn’t believe in the promise of righteousness that God had imputed to them.
So what is my point? Our gospel was preached to those at Mt. Sinai as it is written in Hebrews, and our imputed righteousness wasn’t began in the book of Matthew, but with our father Abraham. It isn’t simply New Testament believers who were credited righteousness, it was all of Abraham’s descendants.
Now we New Testament believers think only those after the cross were credited righteousness, but this simply isn’t true. So if this is the case as taught in our New Testament scriptures, then what was the point of the cross? You can find out at “Why the Cross?”
 Romans 10:3
 Romans 9:32