A “mystery” is something which was previously hidden but has now been revealed. Paul has come to see a certain method in God’s way of dealing with Jews and Gentiles: the fall of Israel has led to the salvation of the Gentiles, and the salvation of the Gentiles is moving the Jews to jealousy. This interdependence of the salvation of Jews and Gentiles is the mystery to which Paul refers here – a mystery which has now been revealed. With the words, “so that you may not be conceited,” Paul is warning his Gentile readers not to exalt themselves above unbelieving Jews, as he had done previously in verses 18-24. When he states, specifically, that Israel has been experiencing a “hardening in part,” he is really saying that the hardening which has kept many Israelites from accepting the gospel has been in the past, is now in the present, and will be in the future only a partial one. For this reason, Jews have been saved, are being saved, and will continue to be saved until the end of time.
From: The Bible and the Future by Anthony A. Hoekema (Grand Rapids: William B. Eerdmans Publishing Company, 1979), pp. 143-144.
