Romans 10:1-4

Paul stresses again (see 9:2) his love for the Israelites and his desire to see them saved. He has no doubt that they are zealous for God, but this zeal is not based on Godly knowledge, they are not doing things according to God's ways (ie according to faith).

They did not know the righteousness of God that comes by faith, so they sought to establish their own. When men do not know God's ways they will always seek to establish their own, then they will claim that their way is God's way. In so doing men put themselves and their ideas as superior to God's ideas.

Christ is the culmination of the Law. The Greek word for culmination can mean either "termination, end point", or "fulfilment". Here it is best to take it as fulfilment. Christ obeyed the law perfectly, the only person ever to do so. He offered Himself as the perfect sacrifice, and so bought redemption for us all. So there can now be righteousness for everyone who believes.

The Jews objected to the fact that hey had to believe in order to be righteous, and to the fact that the Gentiles were righteous because they did believe.