There are three reference points of truth revealed in Scripture that enable us to seek after, find, trust, and rest in the true Christ, the true Mediator, as opposed to counterfeits. The first was the everlasting covenant of grace, and this reveals to our minds the appointment of Christ to be our Mediator and the purpose for which He was appointed to be the Mediator. Here we see how God the Father chose a people out of Adam's fallen race and appointed Christ to be their Mediator. He conditioned all of their salvation upon Christ, the Representative, Substitute, and Surety of God's elect.
The second was His incarnation, His taking into union with His Divine nature a perfect, sinless human nature prepared for Him by God the Holy Spirit in the womb of the virgin Mary. This qualified Him to be our Mediator to fulfill all the conditions of the salvation of God's elect in that He was both God and man. Everything He did on behalf of the elect, He did in His entire Person as Godman/Mediator. The third was the accomplishment of all His mediatorial duties, His mediatorial offices of priest, prophet, and king, on our behalf. God sent Him to fulfill all righteousness for the elect. This includes His obedience under the law, His atoning sacrifice for our sins, His establishing a righteousness whereby the Father could justify the ungodly. It also includes His sending the Holy Spirit to apply the salvation He earned to everyone of the elect in time and His bringing them to final glory in Heaven, all based upon the merits of His righteousness imputed to us and received by faith.
The gospel commands all who hear it to believe in this one Mediator. It commands us and gives every reason to believe God's promise of salvation and final glory conditioned on Christ, based on His righteousness alone. The gospel commands us to repent of ever thinking that salvation or any part of it could have ever been conditioned on us. We are to trust Christ, rest and rejoice in Him and have no confidence in the flesh. After we come to saving faith in Christ and repentance from dead works, we are then commanded to learn all that we can learn of both His glorious Person and the magnitude and value of His mediatorial work summed up in the phrase "the righteousness of God," which His righteousness, the only ground of our salvation and final glory.
This is what the Apostle Paul meant when he wrote, "For I determined not to know any thing among you, save Jesus Christ, and Him crucified" (1 Cointhians. 2:2), and when he wrote, "That I may know Him, and the power of His resurrection, and the fellowship of His sufferings, being made conformable unto His death" (Philippians 3:10). The Apostle Paul knew that all these details, doctrines, concerning Christ's Person and mediatorial work were revealed by God for our growth, our comfort, and our good. Read Hebrews 12:1-3 - This "looking unto Jesus" is not mystical. It has to do with being convinced that we are certain for heaven's glory based on His righteousness alone, because we see Him in His mediatorial glory as "the Author and Finisher of our faith."
The more we look to Him and see ourselves as certain for glory based on His righteousness, the more we are enabled to persevere and grow. The more we learn of both His Person and His the magnitude and value of His righteousness, the more we will have our hearts established with grace. This is how we promote and nurture love, obedience, and worship because all of these acts of godliness are motivated by assurance of salvation conditioned on Christ.
People give lip-service to love for Christ and wanting to know Him and be with Him. They say, "Heaven is to be with Christ, and that's all I care about." They say, "I just want to sit at His feet and bask in His light and love." But how can this be genuine and sincere when they ignore, devalue, scorn, or even ridicule the Scriptural details concerning His Person and work. If Christ is the ONE MEDIATOR between God and men, and He is, it is incumbent upon all of us to seek a saving knowledge of Him as He is revealed in the gospel, and to seek more knowledge of Him as our Mediator. I am interested in and I want to know everything I can know, everything God has revealed, about Christ, the One Mediator between God and myself, the One upon whom all of my salvation rest, the One in whom I trust my soul's eternal destiny. It is important, vital, that we have right thoughts concerning God and Christ, the One Mediator between God and men.
HIS MEDIATORIAL RELATIONSHIP WITH THE FATHER - Christ's mediatorial office is the product of a Divine covenant of redemption, of grace. The entire Trinity had a part in this covenant. We have already seen how God is ONE GOD, but ONE GOD WHO SUBSISTS IN THREE DISTINCT PERSONS. This is the doctrine of the Trinity. Our God is ONE God who subsists as GOD THE FATHER, GOD THE SON, and GOD THE HOLY SPIRIT. One single God, but a plurality of Persons in the Godhead. This is difficult to understand, even mind-boggling when we consider the magnitude of it. We cannot comprehend the height and the depth of this great truth, but we know it is true because it is revealed. Each Person of the Trinity is truly and in every way God in the essence and being of the nature of God. God the Father is no more God than God the Son and God the Holy Spirit. God the Son is not a lesser god, for he would be no god at all. God the Holy Spirit is not a lesser god. God the Father, God the Son, and God the Holy Spirit are all co-equal in every attribute of Deity. It is blasphemy even for us to think that Jesus Christ is a lesser god or that the Holy Spirit is a lesser god. All three Persons of the Holy Trinity are equal and to be worshiped equally as ONE GOD!
As stated, the entire Trinity had a part in the everlasting covenant of grace (Ephesians 1; Matthew 28:19). Here is where we must see the distinction Persons in the Trinity. There has always been and will always be a distinction of Persons within the Godhead. God the Father is not the same Person as God the Son, and God the Son is not the same Person as God the Holy Spirit. They are one and the same God in the essence and nature of their Being, but they are three distinct Persons. Look at this in their distinct operations in the everlasting covenant of grace:
(1) God the Father chose a people out of Adam's fallen race and appointed God the Son to be their Mediator. The Father determined to glorify Himself in the salvation of sinners by conditioning all of their salvation upon His Son. He sent God the Son into the world to fulfill those conditions. So, in the covenant of grace the Father represents the majesty of and exercises the rights of the undivided Godhead, and He appointed and commissioned God the Son for the work. He gave Him a people to be redeemed, prescribed the conditions for that end, sent Him forth as His Son, and yet as His Servant to fulfill those conditions, and promised Him the rewards of His work.
(2) God the Son accepted the office of Mediator. He voluntarily agreed to act in officialsubordination to His Father in order to glorify the Father in the full, free, eternal salvation of all whom the Father had given Him. So His subjection to the Father is not a subjection of nature and essence whereby He would be less than God, less than equal with the Father in every attribute of Deity. But it was a subjection of office for the purposes of redeeming sinners. It was a mediatorial subjection. The Scriptures are full of mediatorial (covenant)language that reveals this official subordination of the Son to the Father.
We might consider here why God the Son agreed to be the Mediator, to become subject to the Father. And remember this official subjection required His incarnation, His being made under the law, His obedience, suffering, and death as the Representative, Substitute, and Surety of His people. He did for "the joy that was set before Him" (Hebrews 12:2). This was a three-fold joy:
(1) His Father's glory as both a just God and a Savior;
(2) His own exaltation as Godman/Mediator; and
(3) the salvation and final glory of all whom the Father had given Him based on the righteousness which He alone established.
(3) God the Holy Spirit agreed to act in official subordination to the Father and the Son to be the one who would apply what the Father purposed and provided and what the Son purchased for the elect. He is represented as being sent forth from the Father and the Son to bring everyone of God's elect to a saving knowledge of Christ and into a right relationship with the Father as both a just God and a Savior based on the righteousness of Christ. He does this in the new birth and continues this work as He renews our minds with the Word of God.
Now in all this we see there is a unity of essence, nature, and will in the Godhead but that acts of this will are ascribed to each distinct Person. Remember, "There is ONE GOD, and ONE MEDIATOR between God and men, the man CHRIST JESUS." God the Father is not the Mediator. God the Holy Spirit is not the Mediator. God the Son incarnate is the ONE MEDIATOR. God the Son did not choose a people. God the Father did. Neither God the Father nor God the Holy Spirit became incarnate, obeyed, suffered, bled, and died. God the Son did. They are one and same in essence and nature, but they are distinct in Persons.
This is why we must see that many times the Scriptures use mediatorial (or covenant) language, and we have to learn to make these distinctions when it does. Consider the following:
John 5:30; 8:54-59; 10:27-30, 17-18 -- greater in office when it relates to the covenant of grace. Equal in essence, subjected in office.
In Philippians 2:5-7, the word "form" denotes essence of nature or attribute; the term, "emptied Himself" refers to the addition of human nature to Christ's Deity. He "emptied Himself" not by subtraction but by addition.
As God, He needed no added glory, but as Godman/Mediator, He was to be glorified with the glory He earned as our Surety.
"everlasting Father" does not refer to the Godhead, but to Christ as the spiritual Father of a spiritual offspring, children of His kingdom. Christ begets spiritual children in the new birth based on the righteousness He established as the government of the covenant of grace was on His shoulders.
John 14:6-9; Hebrews 2:9-10; 10:7 -- This official subordination of the Son to the Father, this subjection of office, not in essence, was necessary because, "It was God's eternal purpose to overrule the fall of man for His own glory, by a signal manifestation of His moral perfections, in justifying 'the ungodly,' through Christ as Mediator" (Buchanan). Herein we see the glory of God revealed in the face of Jesus Christ. Right knowledge of Christ and the Father are inseparable. We can only see and know the Father as we see and know Christ, our Mediator, as the Lord our Righteousness. If we have any compassion for the souls of men and women, we must do our best to make Christ known through the preaching of the gospel.