(These posts are adapted from a presentation Pastor Preus made in Sweden for the North European Luther Academy in 2006 and which was republished in the recent edition of Logia, A Journal of Lutheran Theology. We recommend both groups to the Brothers of John the Steadfast. The other posts in this series are archived in the Brothers’ Cafe under Klemet’s name.)
A Short Case Study: Rome
Let’s look at the dominant practices of the Church of Rome at the time of Luther. Rome will provide an obvious example of the soteriological function of church practices and at the same time show the deep theological import of its key church practices. In the Roman system the papal selling of indulgences served the soteriological purpose of bridging the gap between cross and the sinner. It was a church practice which promoted the Roman doctrine of works-righteousness. So the doctrine of salvation by works and the practice of selling indulgences are interdependent. The function of the sale of indulgences was to provide a manner in which the blessings of the cross could be procured for poor, hapless souls stuck in purgatory. Sin had placed your unfortunate relatives in this place where they were to work away the penalties which the penitential actions of this life, prescribed by the priest, did not do. “As soon as the coin in the coffer rings a soul from purgatory springs,” is the oft quoted jingle employed by John Tetzel. The pope, who is virtually a means of grace in the Roman system, initiated the sale of indulgences and, through their sale, promised to remit the penalties. (It was also the pope, incidentally, who profited from their sale.) So this practice pictures the soteriology of the church and provides the bridge to close the gap between the cross of Jesus and those poor, impatient, purgatorial souls.
Another Roman practice at the time of Luther was the sacrifice of the Mass. The Mass functioned much like indulgences. Instead of buying a certificate authorized by the pope and provided by the church you bought an action authorized by the pope and provided by the church. This action was the unbloody resacrifice of Jesus which was accomplished by the priest through the private saying of the Mass on behalf of the sinner who had money. If you bought a mass you really didn’t even have to participate in it to have its blessings. It was an action done exclusively for the benefit of God. Again, the practice of the sacrifice of the Mass had a soteriological function within the Roman system. The purchase of a Mass provided the sinner with certain assurances that the gap between the cross of Jesus had been bridged and he was closer to heaven. Priests throughout the church would perform countless masses, some monasteries banking these masses for future sale. At the time of Luther one of the monasteries near Cologne had accumulated over 6000 masses.  Since the church hierarchy was the agent which sold the Masses, the practice of purchasing private masses also reinforced in the minds of the people that the way to heaven was through the Roman hierarchy. Doctrine and practice again had merged into one.
Relics are a third practice of the Church of Rome at the time of Luther that merits a brief look. Wittenberg was the home of one of the largest collections of Relics in the Holy Roman Empire and Frederick the Wise, at least in the early stages of the Reformation, was both proud of his collection and dependent upon it for the support of his new and up and coming university. You paid a fee to go see the relics. These relics were authenticated by the church much like a Rabbi will authenticate that a pickle is Kosher. That way you could be certain the relics were not fake. Paying the fee to see the relics bought you papal indulgences which shortened your stay in purgatory. Roland Bainton described Wittenberg’s collection of relics:
The collection had as its nucleus a genuine thorn from the crown of Christ, certified to have pierced the savior’s brow. Frederick so built up the collection from this inherited treasure that the catalogue illustrated by Lucas Cranach in 1509 listed 5005 particles to which the attached indulgences calculated to reduce purgatory by 1443 years. The collection included one tooth of St. Jerome, of Chrysostom four pieces, of Bernard six, and of St. Augustine four; of Our Lady four hairs, three pieces of her cloak, four from her girdle, and seven from the veil sprinkled with the blood of Christ. The relics of Christ included one piece from swaddling clothes, thirteen from his crib, one wisp of straw, one piece of the gold brought by the Wise Men and three of the myrrh, one strand of Jesus beard, one of the nails driven into his hands, one piece of bread eaten at the Last Supper, one piece of the stone on which Jesus stood to ascend into heaven, and one twig of Moses’ burning bush. By 1520 the collection had mounted to 19,013 holy bones. Those who viewed these relics on the designated day and made the stipulated contributions might receive from the pope indulgences for the reduction of purgatory either for themselves or others, to the extent of 1,902,202 years and 270 days. These were the treasures made available on the day of All Saints. 
So the practice of indulgences was a type of means of grace which afforded you blessings which got you out of purgatory and into heaven. It further enforced in the minds of the people that the church hierarchy, which after all authenticated the relics, was the means by which heaven was gained.
Money and church hierarchy – these were the way to heaven. The church prescribed expensive practices in which you had to engage. These practices served to make the cross of Jesus connected with the Christian. That’s the function of church practices. They always serve a soteriological function. They promote doctrine and are inextricably united to it. I could mention penance, the rosary, pilgrimages, the entire system of monasteries, or the whole concept of works of supererogation and prayers to the saints. All of these practices perpetuated, promoted and pictured the theological system of works-righteousness in the Church of Rome against which Luther railed.
Of course Luther opposed these three practices for doctrinal reasons because they went contrary to the gospel. His opposition to indulgences is most apparent in the 95 Theses. Thesis 32 reads, “Those who believe they can be certain of their salvation because they have indulgence letters will be eternally damned together with their teachers.”  He explains this statement, “I maintain this thesis and prove it in the following way: Jeremiah 17 says, ‘Cursed is the man who trust in man and makes flesh his arm.’ We have not other hope of salvation except in Jesus Christ alone, ‘nor is there any other name given under heaven, by which we must be saved.’ May the hope that is based upon dead letters and on the name of indulgences and intercessions perish!”  Observe that the practice is opposed because it conflicted with Luther’s doctrine of the saving gospel.
Luther had particularly choice words for the Canon of the Mass and private masses. Notice again that he attacks the practice of the sacrifice of the Mass because it conflicts with the gospel of Grace.
For God will accept no other mediation and no other mediator than his only son, whom the Father sent into the world and whom he caused to shed his blood for the sole purpose that he might thereby obtain for us the treasure of faith….That, I say, is our gospel that Christ has made us righteous and holy through that sacrifice and has redeemed us from sin death and the devil and has brought us into his heavenly kingdom….Now if this gospel is true then everything that offers another way or another sacrifice must be false. But in the mass the papists do nothing but continually ride the word, ‘we offer up, we offer up’ and ‘these sacrifices, these gifts.’ They keep completely quiet about the sacrifice that Christ has made. They do not thank him. Indeed, they despise and deny his sacrifice and try to come before God with their own sacrifice. 
Relics also incurred his wrath,
Here so many open lies and foolishness are based on the bones of dogs and horses. Because of such shenanigans – at which even the devil laughs – they should have long ago been condemned, even if there were something good in them. In addition, they lack God’s Word, being neither commanded not advised, and are a completely unnecessary and useless thing. The worst part is that relics, like the Mass, etc. were also to have produced an indulgence and the forgiveness of sins as a good work and act of worship. 
Clearly Luther was not concerned merely with benign or innocuous church practices such as folding your hand while praying or making the sign of the cross during the absolution. But neither was Rome particularly adamant about these practical shows of piety. Both Luther and Rome argued over practices which picture or promoted the soteriology of the Roman church. At stake were more than the practices themselves. At stake was the way of salvation.
I recognize that this is a simplistic walk through a complex historical event. I use these historical anecdotes to show the relationship between Roman church practices and the soteriology of Rome.
 Lewis Spitz, Renaissance and Reformation Movements Vol. 2 (Chicago: Rand McNally, 1972) 308
 Roland Bainton, Here I Stand: A Life of Martin Luther (Nashville: Abingdon Press 1950) 69-71.
 Martin Luther, Luther’s Works, American Edition Volume 31 (Philadelphia: Muhlenberg Press, 1957) 28.
 Ibid. 180.
 Luther’s Works volume 36, 313
 SA II Second Articles 22-23, Kolb p. 305