23 and that He might make known the riches of His glory on the vessels of mercy [Christians], which He had prepared beforehand for glory,
The “and” here continues to extend the idea of what God “endured.” Verse 23 is a parallel to verse 22 and a counterbalance to it. Not only did Paul want his readers to know about the purpose of God’s wrath, but God wanted them to know about the purpose of His mercy.
that [purpose] He might make known the riches [wealth] of His glory
God’s purpose in creation is to disclose His glory. We see the glory of four of God’s attributes in verses 22 to 23: wrath, power, longsuffering, and mercy. His glory is exceedingly glorious, especially to the nation of Israel.
on the vessels of mercy,
God prepared a range of His attributes, from wrath to mercy. Believers are in a position to understand the “riches of His glory” in mercy (God’s plan of salvation). Because of this they are “vessels of mercy.” Unbelievers are not.
which He had prepared beforehand [adjusted before]
The words “prepared beforehand” mean to make ready before. The idea is to prepare in advance. The one Greek word for “prepared beforehand” comes from two words: before and to make ready. God in the past has made ready the revelation of His system of salvation.
“Prepared beforehand” is not equivalent to foreordain. The idea is that God adjusted the situation to bring about a result. God is the direct agent of this action. He did this with a single act (aorist indicative). “Prepared beforehand” gives the idea of concurrence (concursus) of all events that brings the resulting conclusion. God in a single act brought forth the process and arranged it in such a way as to receive a reciprocal response.
The original design for salvation was the “riches of His glory.” God never loses control of His system of salvation; He is in complete charge of salvation. No human system or person can alter that plan. The human being has to operate within the parameters of that eternal plan. Chapter 9 presents the sovereignty side of salvation and chapter 10 sets forth the human responsibility side. Mankind does not have limitless options for salvation; we have to function within the singular plan of God.
Note the repetition of the word “glory.” The first “glory” is God’s glory, but the glory in this phrase is our glory. God’s prepared the believer to know His glory.
God’s treatment of people is not arbitrary; He has an eternal plan.
The purpose of God’s patience is to show His surpassing glory in dealing with His plan of salvation. God is a God of mercy and grace in this. He always functions with integrity; He never operates with meaninglessness. He is never arbitrary in His dealings with people. In either wrath or mercy, God always acts consistently with who He is. He always gives opportunity for repentance. God must always act according to who He is rather than out of emotion. God always operates according to the principle of grace.