30 What shall we say then? That Gentiles, who did not pursue righteousness, attained righteousness, even the righteousness which is by faith; 31 but Israel, pursuing a law of righteousness, did not arrive at that law. 32 Why? Because they did not pursue it by faith, but as though it were by works. They stumbled over the stumbling stone, 33 just as it is written, “Behold, I lay in Zion a stone of stumbling and a rock of offense, And he who believes in Him will not be disappointed.” Romans 9:30-33 (NASB)
The Gospel of our Lord Jesus Christ must always be offensive to the unregenerate. It is that offense that makes it clear to people that they have nothing with which to bargain with God. They are sinners lost with nothing to offer the one condemning them. The Gospel, the real Gospel preached with the Law, makes it clear that there is none righteous, no not one; but the Gospel shows that there is one and only one way to be reconciled to God, to be justified before Him. This is the Good News and that one way is via the Lord Jesus Christ alone. No one can work to earn or deserve salvation. No, this salvation is by God’s grace alone according to His divine election, according to His way alone. This is offensive. Let us look at Galatians 5:7-12 in which Paul makes the argument very clear to believers at Galatia who were being victimized by Judiazers making the claim that true salvation was not by Grace alone, but through Grace plus keeping the Jewish law.