It was God's purpose to glorify Himself in the salvation of a multitude of sinners chosen out of Adam's fallen race through Christ as Mediator. God the Father in the everlasting covenant of grace invested God the Son with the office of Mediator. God the Son agreed to act in official subordination to the Father for the purpose of fulfilling the Father's will so that all the perfections of Deity would be honored, magnified, and manifested in the salvation of sinners. God the Father put the whole responsibility of the salvation of His elect upon God the Son. Salvation is conditioned on Christ, the one Mediator between God and men.
We are going to consider the office of mediator as it pertains to the Lord Jesus Christ. His office in general is that of Mediator. Remember, a mediator is one who stands between two parties at variance to act on behalf of both. Christ is the one Mediator between God and men in that He is God to represent God before men and man to represent man before God. There are three main branches of His one office of Mediator. These three offices are PROPHET, PRIEST, and KING. All three offices are included in His title of Messiah, or Christ, the Anointed. All of God's prophets, priests, and kings were anointed when they were invested with these offices. Among men these offices never met in one person. Melchizedek, for example, was a king and priest but not a prophet. David was a prophet and king but not a priest. Aaron was a prophet and a priest but not a king.
Only in God the Son incarnate, the Lord Jesus Christ, do all these offices meet. He is our Prophet to reveal God to sinners. He is our Priest to represent us before God. He is our King to rule over and dispose of all things for the glory of God. The case and condition of God's elect, all whom the Father gave to Him, required Him to fulfill the duties of these offices. The fulfillment of these particular offices is described in Scripture in various ways and titles given to Christ our Mediator. For example, Christ is described as our Representative Head and Substitute. He is called the Surety and Testator of the covenant. He is called our Savior, our Shepherd, our Kinsman/Redeemer, our Propitiation, the Captain of our salvation, our Advocate, and our Intercessor. These are all mediatorial offices and duties of Christ.
To fulfill the duties of these offices He had to be the Representative, Substitute, and Surety of the whole election of grace. Remember, had Christ been only a prophet sent from God to instruct men in divine truth, or had He been only a king to exercise divine rule over a spiritual kingdom, He might have fulfilled His mission as the representative of God without becoming the Substitute of men. This is where we see that the ground of His mediatorial glory was His PRIESTLY office. He is not only our Prophet and our King, but He is our High Priest.
"Christ, as Mediator, was 'made under law' as the substitute, representative, and surety, of His people" (Buchanan). Because of our fall in Adam, mankind by nature lies in a state of condemnation and guilt, alienated and enemies of God. In Adam we rebelled and declared war on God. The whole human race in Adam was doomed to eternal punishment and damnation unless God, the offended party, would intervene and provide a way of redemption and salvation. Remember, God had determined before the fall to save a people of His own sovereign choice out of Adam's fallen race. But being a just and righteous God, He could not save them apart from His law and justice being satisfied. God must be holy and just. He can by no means clear the guilty. God is loving and gracious, but He cannot exercise His love and grace at the expense of His justice and holiness. God must find a way that He can be both holy and gracious, just and merciful, righteous and loving. He must be both a just God and a Savior, or He cannot save at all. Therefore, He had to provide a mediator, one who could not only stand between God and men, but who could also represent men, one who would substitute Himself in their place and satisfy law and justice on their behalf.
The whole purpose of His mediation was to reconcile God to men and men to God. In order to accomplish this He had to establish the ground of peace (2 Corinthians 5:21). He had to remove the ground of condemnation and establish the ground of justification for His people. He had to bring about a propitiation towards God. He had to satisfy God's law and God's justice by fulfilling the precepts of that law perfectly and by suffering on the cross for the sins of His sheep. Satisfaction means He secured the salvation of His people and laid a sure ground of pardon, acceptance, and entitlement for all that should believe in His name. This ground is not their faith. It is His righteousness imputed and received by faith. His fulfilling the duties of His priestly office is the establishment of this righteousness that demands the salvation and final glory of all for whom He died to the praise and glory of the Father.
His fulfilling the duties of His prophetic and kingly offices is directly grounded upon the establishment of this righteousness. Without this righteousness, as a prophet, all that He could reveal is the wrath of God (Romans 1:18). Without this righteousness, as a king, all that He could do is exercise wrath against sin. So we see that His offices as Mediator and the duties He performs are all dependent upon His establishing a righteousness that enables the Father to justify the ungodly. All of His offices testify of God's absolute, free, and sovereign grace. They prove and illustrate in every particular how all of salvation is conditioned on Christ and no part of salvation is conditioned on the sinner.
Consider Him as the Covenant-Head of the elect. This is sometimes referred to as the doctrine of Federal Headship. Christ is often said to be Head of the church (Ephesians 1:22-23; Colossians 1:18). He is the Head of the Church in the sense that He communicates life to it, and in that He oversees and protects the church. He is the source of all life for His people. He sustains us and supplies us with all grace. He is the Head of the Church in the sense that He rules over us and leads us. We are His subjects. He is the Head of the Church in the sense that He is our Husband and we are His Bride. His headship in these senses chiefly belongs to His Kingly office. But He is also our Representative-Head in that all of God's elect were considered in Him, and represented by Him, when He made a covenant with the Father for us. When He engaged Himself to do and suffer all that was required for our salvation, He agreed to do it not only on our behalf, but in our name and in our nature, as our Substitute. We see this in several particulars:
I. IN ELECTION (Isaiah 42:1-4; Ephesians 1:3).
God the Son was first chosen and divinely appointed by God the Father (Isaiah 42:1-4). His people, God's elect, were chosen IN HIM as their Representative (Ephesians 1:3-4). Christ was set up as Mediator not as a private person but as a Representative-Head. When God chose His people out of Adam's fallen race, they did not exist personally, but Christ did, and He represented them. Therefore, they were capable of being chosen IN HIM.
How could we have been blessed with all spiritual blessings when we did not exist?
We were blessed in Christ our Representative.
This shows us that the heart of election is not merely that God chose a people unconditionally before the foundation of the world. This certainly is essential to a Biblical understanding of election, but it is not, in and of itself, the heart of election. The heart of election is the elects' union with Christ. Here we the purpose of God in choosing a multitude of guilty, hell-deserving sinners out of Adam's fallen race, and we see His purpose in saving them. His purpose is to glorify Himself in the salvation of sinners based on the righteousness of their Representative-Head, the Lord Jesus Christ (2 Corinthians 4:6). We see then that God's glory is the main issue in election and salvation, and Christ's righteousness is the main issue in the glory of God in salvation. It is based upon the righteousness of Christ that God the Father is enabled to be both a just God and a Savior. This is why we cannot know God as a loving, saving Father apart from Christ (Matthew 11:27; John 17:1-4).
We hear some people claim that they believe election is unconditional and that salvation is conditional, conditioned upon the sinner's faith. They cover themselves by adding that the faith is the gift of God. It is true that saving faith is the gift of God, but the faith that God gives His elect believes that Christ's blood and righteousness makes the only difference between saved and lost. The faith God gives His elect believes that Christ by Himself met all the conditions of salvation and secured for the believer all grace here and all glory hereafter. We see, then, that it is impossible to claim that election is unconditional while claiming salvation is conditioned on the sinner's faith. Christ, according to His union with the elect, secured everything necessary for their salvation, including faith. To say that election is unconditional and that salvation is conditioned on faith is more subtle than most heresies, but it is just as deadly. It is only as we see the heart of election that we see how the mediatorial glory of Christ revealed in the Gospel puts all things in salvation, including the work of the Holy Spirit in us, in their proper place. This is the only way that God can be glorified as both a just God and a Savior, Christ can be exalted and given the preeminence as Lord, and all ground of boasting be excluded in the redeemed sinner.
II. IN PROMISE (2 Corinthians 1:20).
The everlasting covenant of grace is a covenant of promise made to the elect of God as they were considered in Christ. All the promises of the covenant were made to Christ as the Representative of the elect before the world began (Titus 1:2; 2 Timothy 1:9). None of these promise then were conditioned on them but all were conditioned on Him, and, therefore, sure and certain (2 Samuel 23:5; 2 Corinthians 1:20).
It is essential to our salvation that our Mediator be our Representative-Head. Christ in the everlasting covenant of grace engaged Himself as our Representative and Substitute to obey and suffer all that God required of us. All that He did as our Mediator, He did not as a private person but in our name and in our nature as our Representative. This may be proven by comparing Christ's representative work with Adam's. Read Romans 5:12 -Adam, the first man, was the federal head and representative of the whole human race, all of his natural off-spring. Therefore all men by nature are guilty and condemned based upon the one act of Adam's sin. Adam's guilt is imputed and his sinful nature is imparted to everyone whom he represented (the whole human race) WITH NO CONSIDERATION OF OR CONTRIBUTION FROM THEIR PERSONAL SINS. Death spread to all men because all sinned in Adam, not in our own persons, but in the person of Adam, our representative. We were not yet born, so our condemnation could not have come upon consideration of or by contribution from our personal sins.
By the same principle, God's elect are made righteous and justified based upon the one act of Christ's obedience and death. Christ's righteousness is imputed and His holy nature is imparted to all whom He represented (the whole election of grace) WITH NO CONSIDERATION OF OR CONTRIBUTION FROM THEIR PERSONAL OBEDIENCE. The righteousness of Christ demands the justification and life of everyone whom He represented because they obeyed the law perfectly and suffered all punishment due unto their sin, not in their own persons, but in the Person of Christ, their Representative. Many of God's elect were already dead and many had yet to be born when Christ established this righteousness. Their justification could not have come upon consideration of or by contribution from their personal obedience. Read Romans 5:18-19 -
A. One sin, one righteousness (Romans 5:18) - Paul concludes it is certain that Adam's sin is ours by representation and imputation, and that one sin brought all whom Adam represented into a state of condemnation before God. Even so, or likewise, according to the very same principles of representation and imputation, it is certain that Christ's righteousness demands the free justification and life of all whom He represented. Notice carefully, God DOES NOT say that the free gift of righteousness is merely provided for all IF they meet the condition of faith. God says emphatically that the free gift of righteousness "CAME UPON," or is actually communicated to "ALL UNTO JUSTIFICATION AND LIFE." Whoever or however many he means, we know that they are those who will without fail come to justification and eternal life based on the one righteousness of Christ imputed.
Those whom Christ represents were raised again unto justification 2,000 years ago at Calvary, not in their own persons, but just as surely in the Person of their Representative with whom they are one. THEY SHALL BE JUSTIFIED IN THEIR OWN PERSONS BECAUSE CHRIST'S RIGHTEOUSNESS WAS ESTABLISHED FOR THEM AND SHALL BE IMPUTED TO THEM. Christ's righteousness demands their justification and life according to God's promise which is perfectly consistent with His holiness and truth.
B. The legal transaction (Romans 5:19) - "Made sinners ... made righteous" means legally constituted, or put into a position of guilt and righteousness respectively. This language is much the same as the apostle used in 2 Corinthians 5:21. The whole context here points not to a moral change but a legal standing. No one can make this more simple and easy to understand than the Apostle Paul does in this verse. Adam's sin is the only ground of condemnation, while Christ's righteousness is the only ground of justification. Adam's sin demanded death, guilt, alienation from God, and wrath for "the many" whom he represented, because his sin was their sin, not personally, but by representation and by imputation. Christ's righteousness demands life, justification, reconciliation, blessedness, eternal peace and joy for "the many" whom He represented, because His righteousness is their righteousness, not personally, but by representation and by imputation. So the very heart of Paul's argument in 5:12-21 is contained in verses 12, 18 and 19.
All the elect, all whom Christ represented, shall in time, in each successive generation, be justified in their own persons based on the imputed righteousness of Christ. This blessed truth of the absolute certainty of salvation for all of God's elect, grounded upon the imputed righteousness of Christ, DOES NOT shut any sinner out for two very specific reasons:
1. God freely invites and commands all who hear these truths to seek and find salvation based solely upon this righteousness revealed (Romans 3:22; 4:23-25; Isaiah 45:20-22; 46:12-13).
2. God forbids sinners to seek salvation based on any other ground no matter how noble it may seem and no matter how men may esteem it (Galatians 6:14; Isaiah 45:24).
It will help us immensely to see in 5:12-19 that no reference made to our personal sins or our fallen nature, nor to our potential to and practice of sin. Paul proves over and over again that we are guilty and condemned by the one sin of the one representative, Adam. Now the following constitutes the joy and peace which comes from believing. This is comfort for those sinners who have truly been slain by the law. Here, we can rejoice in the absolute certainty of salvation. There is also no mention whatsoever of our personal righteousness or good works, no reference whatsoever to any inherent righteousness or any potential to or practice of morality. God the Holy Spirit by the Apostle Paul proves over and over again that the righteousness of ONE is made or legally imputed to the "many" as the only ground of salvation. We must see that this truth does not diminish or exclude the demerit and abomination of our personal sins. Personal sins only add to the guilt and condemnation of all men in Adam, but they are not the ground of our condemnation. Also, this truth does not diminish or exclude the value and necessity of personal obedience of all who are saved and justified, but personal obedience is not the ground of salvation and justification. Paul is not teaching that Christians are not obligated to obedience. He is not teaching that obedience and good works are not needed. He is teaches that obedience and good works are needed as evidences of salvation and as the grateful responses of a redeemed sinner, but they are not needed as forming any part of the ground of salvation. Only Christ's righteousness can have that exalted place, that He might have the preeminence.