Romans 11:25–32 NASB95 25 For I do not want you, brethren, to be uninformed of this mystery—so that you will not be wise in your own estimation—that a partial hardening has happened to Israel until the fullness of the Gentiles has come in; 26 and so all Israel will be saved; just as it is written, “The Deliverer will come from Zion, He will remove ungodliness from Jacob.” 27 “This is My covenant with them, When I take away their sins.” 28 From the standpoint of the gospel they are enemies for your sake, but from the standpoint of God’s choice they are beloved for the sake of the fathers; 29 for the gifts and the calling of God are irrevocable. 30 For just as you once were disobedient to God, but now have been shown mercy because of their disobedience, 31 so these also now have been disobedient, that because of the mercy shown to you they also may now be shown mercy. 32 For God has shut up all in disobedience so that He may show mercy to all.

Mystery - greek musterion; some sacred thing hidden or secret which is naturally unknown to human reason and is only known by the revelation of God. (Zodhiates, The Complete Word Study Dictionary)

Rom 11:25-27

The Meaning:  

•    God’s partial hardening of Israel, which was always part of His redemption plan but was unknown before the gospel, is TEMPORARY until the full number of Gentiles comes to faith in Christ.

•    The believers need to know and be reminded of God’s plan to keep them from becoming ARROGANT.

Application: When we are ignorant of or reject God’s revelation about man’s nature, then arrogance, RACISM, and DIVISION are inevitable.

Acts 17:26 NASB95 26 and He made from one man every nation of mankind to live on all the face of the earth, having determined their appointed times and the boundaries of their habitation,

Romans 3:23–24 NASB95 23 for all have sinned and fall short of the glory of God, 24 being justified as a gift by His grace through the redemption which is in Christ Jesus;

Romans 11:28-29

Meaning: In regards to the GOSPEL, Israel is God’s enemy, but in regards to ELECTION, they are still His beloved. 

Application: When we evaluate people, our standpoints or perspectives are always LIMITED. Since only God can see them all, exercise HUMILITY.

Colossians 1:21–22 NASB95 21 And although you were formerly alienated and hostile in mind, engaged in evil deeds, 22 yet He has now reconciled you in His fleshly body through death, in order to present you before Him holy and blameless and beyond reproach—

Romans 11:30-32

Meaning: All human beings share two things in common: 1) all have been DISOBEDIENT to God, and 2) all have received God’s MERCY.