The grace wherein we stand is the free grace of God that justified us on the sole ground of Christ's righteousness (Rom. 3:25-26). When we say “the righteousness of Christ,” we mean to include His obedience in life and His obedience in suffering and death. The law must be honored. We dishonored it. God’s justice demanded satisfaction. We could not give it. God chose us “in Him” (Eph. 1:4). Christ assumed our case. He stood in our place before God (Isa. 42:6; Jn. 10:15,29). He acted on our behalf (Rom. 5:12-19; Eph. 5:25-33). Therefore, our sins were made His (2 Cor. 5:21). The law that we disobeyed cursed Him in our place. The honor to that law, which we would not and could not give, was given by Christ on our behalf by His obedience unto death (Philippians 2:6-8). This is the justifying righteousness of Christ that is ours by sovereign grace (Rom. 3:24; 5:17). This justifying grace is the ground of our peace. The grace to which we have had access is our state of justification before God. That "we" are justified and not "all" is not for anything in us. As Charles Hodge said, "We did not open the way or introduce ourselves into this state. We were brought into it by Christ."
The words, "we rejoice in hope of the glory of God," express a joyful confidence and assurance of eternal and ultimate salvation (Heb. 7:25). This reward of our justification is consistent with what God received from Christ.
Let me illustrate. As a junior engineering manager, I was reviewing a proposed wage increase, for an engineer that reported to me, with a more senior manager. The proposal had to be entered into an automated system. My proposed increase was greater than the recommended maximum. There was a field in the entry form for handling such cases. My proposal required a justification. But there was only enough room for three or four words. As I sat there with the more senior manager, I was doing mental gymnastics in real time trying to come up with a convincing basis for my out-of-bounds recommendation in three to four words. I knew that my recommendation would have to pass the scrutiny of the most senior manager in the organization. As we two looked at the screen together, the other manager reached over to the keyboard and entered the words, "appropriate amount"!
In His prayer to His Father in John 17:22, our divine Mediator said, "The glory which thou gavest me I have given them." This is Christ’s proposal to His Father for the blessing He would give to His people. What reason does God give to our faith for such an extravagant proposal, which both swoons the heart and exceeds all bounds of measurement? He looks at His Son. He sees what He has done. And He records this in His word, "Appropriate amount!" That is what is meant here. Believers are justified by Christ's righteousness alone. They stand before God in Him. God sees them as He sees His Son. He received from His Son satisfaction to His justice and honor to His law in their place and on their behalf. Now a reward consistent with His accomplishment is proposed: eternal glory with Christ (Jn. 17:22; 2 Tim. 2:10; 1 Pet. 5:10)! What can be given as the reason for such an immeasurable blessing? "Appropriate amount!" But how does scripture record this for us? “He that spared not his own Son, but delivered him up for us all, how shall he not with him also freely give us all things?...It is Christ that died, yea rather, that is risen again, who is even at the right hand of God, who also maketh intercession for us” (Rom. 8:34)! Glory in this! Rejoice in this hope! It is the appropriate amount that is consistent with the offering and obedience of God’s own Son! And it is the possession of every believer in Christ, because all that was theirs became His, and all that is His is now theirs. Christ and His people are one (Jn. 17:22)!