The Bible tells us that "Jesus has obtained a more excellent ministry, because he is the mediator of a better covenant, which is based on better promises" (Hebrews 8:6-8). This makes us realise that, if we want an involvement with God that accords with God's grace and will, then we must comply with the covenant Jesus Christ has mediated to us.
If we are not compliant with the covenant mediated by Jesus, then we are "dead in trespasses and sins... sons of disobedience... children of wrath... strangers to the covenants of promise, having no hope and without God in the world" (Ephesians 2:1-3,11-12).
Nobody in their right mind would want to have that kind of relationship with God, would they?
By contrast, if we obey the covenant of Christ, then we "have our access to the Father in one Spirit... no longer aliens and strangers, but fellow citizens with the saints and are of God's household" (Ephesians 2:4-10, Ephesians 2:18-22).
People either accept the covenant and are subject to grace as saints and sons of God through obedience of faith, or they violate the covenant and are subject to wrath as enemies of God through disobedience and unbelief. Either way they are involved with God within the scope of Christ’s covenant.
Our right involvement with God is often described as a "covenant relationship with God." The Holy Spirit never speaks of "a covenant relationship". The unscriptural term may be connected to the idea that the covenant of Christ has application only to those who honour it. The Bible's view is quite different...
"There is one mediator between God and men" and he became "a ransom for all" and through him God "desires all men to be saved and to come to a knowledge of the truth" (1Timothy 2:4-6).
How can a covenant not apply to one to whom it has been mediated? To whomever the covenant is mediated, upon them the covenant is binding.
Christ's blood is the "blood of the new covenant" (Matthew 26:28). His blood was shed "for the whole world" (1John 2:2).
How can a covenant not apply to one for whom the blood of the covenant was shed? For whomever the blood was shed, to them the covenant is ratified.
God made a promise to all mankind (John 3:16). God backed up that promise by making an oath to Christ concerning the validity of his high priesthood under the new covenant (Hebrews 6:16-20, cf Hebrews 7:21-22).
How can a covenant not apply to one to whom God has made a promise that the covenant contains and guarantees with an oath? Whoever are able to believe like Abraham the promise and oath of God, to them the covenant applies.
Christ, at his second coming, will deal out "retribution to those who do not know God and to those who do not obey the gospel of our Lord Jesus" (2Thessalonians 1:8-10).
How can a covenant not apply to one who is condemned for not obeying it? Whoever is accountable for not obeying the covenant, to them the covenant applies.
The old covenant, mediated by Moses, contained both "blessings and curses" (Deuteronomy 28:58-63, Deuteronomy 30:9-10,15-20).
The new covenant, mediated by Christ, also contains blessings and curses. Fortunately the blood of that covenant, Christ’s own blood, provides the means of removing its curses and bestowing its blessings (Galatians 3:6-28).
The covenant applies not only to those whom it blesses, but also to those whom it curses so that the curses can be replaced with the blessing.
We need to identify exactly what is the covenant which Christ mediated. I have heard some very complicated answers to that, involving various distinctions, divisions, and dispensations of the word of Christ. However the correct answer is quite simple. The covenant that Christ mediated is the gospel of Christ.
Paul was unaware of any distinction between the gospel of Christ and the new covenant of Christ. Paul writes to the "beloved of God in Rome, called as saints" and says, "I am eager to preach the gospel to you also who are in Rome" (Romans 1:7,15).
How could this be, if the gospel for sinners and the covenant for saints were two different and separate things? The world is therefore not divided into those who are subject to the gospel and those who are subject to the covenant, for the gospel is the new covenant and all men are subject to it.
Again, Paul refers to "ministers of the new covenant" (2Corinthians 3:6) but later refers to this ministry as the preaching of the gospel (2Corinthians 4:1-6).
All men have an involvement with God because the Son of God has shed his blood for all and thereby mediated the new covenant to all.
The gospel of Christ is a covenant which God has made binding on all people, therefore all people are involved with God either as his enemies and under a curse because they regect the gospel, or as his sons and under grace because they accept the gospel.
Our involvement and relationship with God is determined by our covenant with God, a covenant not invented or negotiated by us but mediated to us from God by Christ. We can make sure that we have a right relationship and involvement with God simply by believing and obeying the gospel which God has so graciously provided as the only valid covenant between us and him.
This covenant was ratified by God's own oath and the shed blood of his own Son.
How kind God is to have done this for us, and what fools we are if we do not yield ourselves body and soul to this wonderful covenant with God.