How do we know the promises of God have not failed?

In Romans 9:6, Paul asserts that the word of God has not taken none effect, emphasizing that while Israel as a nation may have failed, God's purposes are on course through a faithful remnant. This notion is also reinforced in Romans 3, where Paul answers the question of what advantage the Jews have by identifying the oracles of God entrusted to them. The critical understanding is that being part of Israel is not merely a matter of ethnicity but involves being chosen in Christ before the foundation of the world—signifying that God's promise of salvation stands firm despite Israel's shortcomings.