There is a principle operating in scripture which emulates from God called the ‘one and the many’. God is triune, meaning that while we speak of only one God, or more correctly ‘the God who is one’, we are actually speaking of three persons of the trinity, namely the Father Son and Holy Spirit.
The oneness of God is an expression of their complete unity but also of each one’s ability to represent fully the other two. This representation is such that to experience a relationship with one is to experience it with all. That is what Jesus meant when he said to Philip “if you have seen me you have seen the Father”. So, since the Father Son and Holy Spirit all share the same nature which we call God or if you like ‘Godness’, what is true for one is true for all. Likewise Adam fully represents all mankind. Therefore if Adam sins and becomes a sinner then all who share Adam’s nature are also sinners. This truth is both a declaration of status before God and an accurate description of our nature in practice. So we sin because we are sinners and we are sinners because we share the same nature as Adam. Therefore if Adam is condemned we are all condemned since we are of his family and share in his status and nature.
The good news for all Christians is that God also applies the principle of the one and the many to the family of Jesus. Jesus takes on flesh or more accurately, becomes fully human and partakes of every aspect of our nature except our sinfulness. He is not a sinner according to status because he is the Son of God and the proof of this is that he does not sin. Being fully human he is called the second Adam, or, if you like, the ultimate Adam and we who are humans are invited by God to be reborn into his family and share in his status and nature. In other words through adoption, we can loose our membership in Adam I’s family and become members of Adam II’s. Once we gain membership into the second Adam’s family we are declared to be righteous because he is righteous.
This declaration will also one day be an expression of how we really are in practice but for the time being, since we continue to live in first Adam’s world we will live contrary to our new nature and sin.
The principle of the one and the many applies also to acts committed by the two Adams. In the case of Adam I, the one act of rebellion in the garden cut all men off from God and made them rebels. Likewise the one act of righteousness by Adam II namely his perfect obedience, culminating and exemplified in his death on the cross, brings all his people back and makes them want to be obedient.
The first Adam not only introduced sin but also death, which is its penalty. He also prooved that it was never going to possible for mankind to live under law. Even though Adam was created morally perfect, as soon as the law was introduced it caused resentment and rebellion. In fact Paul tells us that sin was dormant until the law was introduced and then it sprang to life like a lion on the prowl and brought death.
The solution then is not to disregard the law since that would bring chaos, but to satisfy the law through one who doesn’t become resentful under it, namely Jesus. With the law satisfied God is now free to introduce another law, the law of grace.
This allows us, among other things to freely love God from the heart rather that under compulsion and also to love others in the same way. In doing that we actually begin to obey the law naturally, almost without realising we’re doing it and become suitable candidates for eternity.
Where sin abounded grace abounded all the more!!