Doctrine at Reformation

I'm afraid I can't tell you "exactly" what anybody's doctrine was. Doctrine is never quite that simple. There are always varieties of viewpoints within any given theological camp. Also, the doctrine of the church is so detailed that it would take volumes and volumes to begin tackling it. That being said, I think I can give you some helpful highlights and trends that will give you a basic idea of the theological landscape during the Reformation and since.
Some of the hallmark differences between the Reformers and the Roman Catholic Church in the early 16th century are embodied in the so-called five solas (sola is Latin for "alone") of the Reformation. In English, these are the doctrines that:

1. Justification is by means of faith alone.
2. Salvation is won on the basis of grace alone.
3. Scripture alone is authoritative and infallible for the church's use in binding the consciences of men.
4. Christ alone is the mediator between God and men.
5. True doctrine gives glory to God alone.

In the Roman Catholic system of salvation, justification was God's recognition that a person actually was righteous, as demonstrated and merited by his good works. God declared a person "not guilty" because the person was in reality "not guilty." In the Reformed system, justification was God's legal declaration that a person had been acquitted of guilt on the basis of Christ's substitution for him. In reality, we are all guilty, but God judged Christ in our stead, calling him "guilty" so that we might be called "not guilty." Whereas the Roman Catholic system held that God judges all men on the basis of their own works, the Reformed system held that God judges believers on the basis of Christ's work. We get credited with his righteousness; he got credited with our sin. Faith alone and grace alone deal with this controversy.

The controversy of Scripture alone had to do with the Roman Catholic Church's claim to infallibility and authority, particularly with its appeal to authoritative "divine tradition" that it claimed had been handed down (originally orally) from Jesus and/or the apostles. "Divine tradition" was put on par with Scripture as a rule of faith and life. The Reformers taught that this authority and infallibility rested in the Bible alone.

The point of Christ alone had to do with the general attitude of the Roman Catholic Church that tended to play up the roles of such individuals as the pope, Mary, saints, etc. in such a way as to ascribe mediatorial roles to them. For example, the supererogatory works of the saints were said to be stored in the treasury of merit, so that the grace thereof might be used to change a sinner's standing before God. This is still the basis on which the Church sells indulgences. When a person buys an indulgence, the Pope sells him a bit of merit from the treasure of merit to reduce the sinner's time in purgatory. This is merit that was claimed to have been earned by people other than Christ, and was used to reduce temporal suffering. In this way, the dead saints played mediatorial roles that the Reformers insisted the Bible reserved to Christ alone.

Glory to God alone was sort of an overarching idea that had to do with the exaltation of people such as the saints and the pope, as well as with the Roman Catholic doctrine of salvation that ascribed real merit to man in his own salvation. According to the Reformers, God alone deserved the glory. Man bore no credit in his salvation or in the salvation of others. Any system of doctrine that ascribed to man a meritorious role also ascribed to man a reason to be glorified. The true system of doctrine had to be one that ascribed all the glory to God alone at every turn.

Since the Reformation, Roman Catholic doctrine has not changed from these stances, at least not officially. If anything, it has become more official and more entrenched. Because the Roman Catholic Church believes that it cannot err when it speaks authoritatively on matters of doctrine, it cannot ever admit to a change in official doctrine. Of course, we Protestants accuse them of changing their doctrine all the time, even of contradicting it. But the response is generally that the prior doctrine was never officially authoritative, or that their modern alterations of it are actually elucidations of what the doctrine had always been (i.e. modern Protestants misunderstand the former doctrine).

Reformed doctrine, however, has continued to be refined, clarified and corrected in many cases, and in many others it has been corrupted and confused. This great variety is due at least in part to the fact that the tradition of the Reformation resulted not in one Reformed church, but in thousands of Protestant denominations. Because there is no unchangeable authority dictating which interpretations of the Bible are acceptable, Protestant denominations have run the gamut of theology. You can find a Protestant church somewhere that believes almost anything you can imagine. This is unfortunate, but it is certainly better than being stuck under an unchangeable system that long ago abandoned the only gospel that can save. At least the gospel can still be found in many Protestant churches, despite the fact that they are also riddled with error. Those churches whose doctrine has changed least since the Reformation are the Reformed churches (such as conservative Presbyterians, Dutch Reformed, Swiss Reformed, Scottish Presbyterians) and conservative Lutheran churches (whose doctrine largely still reflects the theology of Melanchthon, who took over after Luther's death).