“My little children, I am writing these things to you so that you may not sin. But if anyone does sin, we have an advocate with the Father, Jesus Christ the righteous, and he is the atoning sacrifice for our sins, and not for ours only but also for the sins of the whole world” (1 John 2:1- 2).
The Doctrine
At the heart of the Gospel is the atonement. The atonement is the teaching that through the life, death, and resurrection of Jesus Christ, we are made at one with God
The Nicene Creed only says this about it, “For us and for our salvation he came down from heaven” and “was crucified under Pontius Pilate.”
It was understood that Jesus died for our sins, but a full understanding of how he did it, was not handed down.
Redemption
The first theory was the Ransom Theory. Adam sold us into slavery to Satan and Jesus paid the ransom to free us. He redeemed, or bought us back.
A version of this is called Christus Victor. It is similar to the Ransom Theory, Satan held us in bondage in a spiritual prison, and Jesus came and conquered the devil. This is much more biblical.
But it doesn’t exhaust the depth of the atonement. The following theories I would put in addition to the Christus Victor view.
Moral Influence
The Moral Influence Theory says that the purpose of Christ’s death was to influence humankind toward moral improvement. I don’t know if was the purpose of Christ’s death, but it was one of the results.
Substitutionary Atonement
The Moral Government Theory holds that God publicly demonstrated his displeasure with sin by punishing his own sinless and obedient Son as a propitiation. As Charles Finney explains, “the atonement is the governmental substitution of the sufferings of Christ for the punishment of sinners.”
A Combination of the Theories
I believe that all of these played a role in the atonement. We were in fact slaves to sin, Satan and death, but Christ set us free from that slavery. And it was a substitution of the sufferings of Christ for our separation from God. And of course this resulted in a powerful, moral influence on Christ’s followers.