Up until then the ransom theory of atonement was the Catholic teachings.
I'm sure Thomas can correct me, and provide some fine details, but that is not far off.
Well it's two lines, I assume, copied from a long document, the wiki article on
Salvation in Christianity, so my suggestion would be for anyone interested to read on to the end of the document for themselves, no need to rehearse line by line here.
Not wanting to post extensively on the Islamic Board, but in response to the enquiry, suffice to say there is no one, single, definitive dogma of Salvation, simply because that truth of the Church was never challenged by heresy. Rather, it was always a given and understood that Christ died for our sin. A foundational commentary was given by Irenaeus of Lyon (130-202AD) – the Recapitulation Theory appeals to me particularly – and Fathers, Doctors, saints and sages have given rise to different doctrinal approaches through their own exegesis.
With regard to the Atonement, to quote the
Catholic Encyclopedia:
At first we have the central fact made known in the Apostolic preaching, that mankind was fallen and was raised up and redeemed from sin by the blood of Christ... By whatever names or figures it may be described, that work is the reversal of the Fall, the blotting out of sin, the deliverance from bondage, the reconciliation of mankind with God. And it is brought to pass by the Incarnation, by the life, the sufferings, and the death of the Divine Redeemer. All this may be summed up in the word Atonement. This, is so to say, the starting point.
The base text, if you like, is from the Council of Trent in 1547:
Whence it came to pass, that the Heavenly Father, the Father of mercies and the God of all comfort (2 Corinthians 1, 3), when that blessed fullness of the time was come (Galatians 4:4) sent unto men Jesus Christ, His own Son who had been, both before the Law and during the time of the Law, to many of the holy fathers announced and promised, that He might both redeem the Jews, who were under the Law and that the Gentiles who followed not after justice might attain to justice and that all men might receive the adoption of sons. Him God had proposed as a propitiator, through faith in His blood (Romans 3:25), for our sins, and not for our sins only, but also for those of the whole world (I John ii, 2). (Sixth Session:
Decree on Justification, Chapter II:
On the dispensation and mystery of Christ’s advent)
The shortest and most succinct theory is offered in the Catechism of the Catholic Church:
It is love "to the end" that confers on Christ's sacrifice its value as redemption and reparation, as atonement and satisfaction. He knew and loved us all when he offered his life. Now "the love of Christ controls us, because we are convinced that one has died for all; therefore all have died." No man, not even the able to take on himself the sins of all men and offer himself as a sacrifice for all. the existence in Christ of the divine person of the Son, who at once surpasses and embraces all human persons, and constitutes himself as the Head of all mankind, makes possible his redemptive sacrifice for all."
(CCC Part 1, Section 2, Chapter 2, Paragraph 616)
To be even briefer, Love is the answer, and it is for each one of us to search our hearts as to its meaning.