Why did Israel fail to obtain God's righteousness according to Romans 10?
Israel failed because, being ignorant of God's righteousness, they went about to establish their own righteousness through works and law-keeping rather than submitting to God's righteousness by faith. Christ is the end of the law for righteousness to everyone who believes, but they left faith out, and without faith it is impossible to please God.
Les teaches that Israel had never opened up their thinking to understand what the Book said. Romans 10 says they were ignorant of God's righteousness and went about to establish their own righteousness, refusing to submit themselves to the righteousness of God. Christ is the end of the law for righteousness to everyone who believes. Israel tried to do it with their own works and left faith out of the picture. They kept the Feast Days, followed the sacrifices, and followed the Law to the letter, but with no faith. Without faith, it is impossible to please God. Christ was the object of faith Israel was expected to embrace. He came proving who He was and was the fulfillment of over 360 distinct Old Testament prophecies. They should have recognized Him when He began His ministry, but they did not know their Bible. Les compares this to most people today who do religious rituals without faith, which counts for nothing.
For they being ignorant of God’s righteousness, and going about to establish their own righteousness, have not submitted themselves unto the righteousness of God.