The fundamental belief of medieval Christians was that the Church as an institution was the only path to spiritual salvation. It was much less important that a Christian understand any of the details of Christian theology than it was that they participate in Christian worship and, most importantly, receive the sacraments administered by the clergy. Given that the immense majority of the population were completely illiterate, it was impossible for most Christians to have access to anything but the rudiments of Christian belief. The path to salvation was thus not knowing anything about the life of Christ, the characteristics of God, or the names of the apostles, but of two things above all else: the sacraments and the relevant saints to pray to.
The sacraments were, and remain in contemporary Catholicism, the essential spiritual rituals conducted by ordained priests. Much of the practical, day-to-day power and influence exercised by the Church was based on the fact that only priests could administer the sacraments, making access to the Church a prerequisite for any chance of spiritual salvation in the minds of medieval Christians. The sacraments are:
- Baptism - believed to be necessary to purge original sin from a newborn child. Without baptism, medieval Christians believed, even a newborn who died would be denied entrance to heaven. Thus, most people tried to have their newborns baptized immediately after birth, since infant mortality was extremely high.
- Communion - following the example of Christ at the last supper, the ritual by which medieval Christians connected spiritually with God. One significant element of this was the belief in transubstantiation: the idea that the wine and holy wafer literally transformed into the blood and body of Christ at the moment of consumption.
- Confession - necessary to receive forgiveness for sins, which every human constantly committed.
- Confirmation - the pledge to be a faithful member of the Church taken in young adulthood.
- Marriage - believed to be sanctified by God.
- Holy orders - the vows taken by new members of the clergy.
- Last Rites - a final ritual carried out at the moment of death to send the soul on to purgatory - the spiritual realm between earth and heaven where the soul's sins would be burned away over years of atonement and purification.
Unlike in most forms of contemporary Christianity, which tend to focus on the relationship of the individual to God directly, medieval Christians did not usually feel worthy of direct contact with the divine. Instead, the saints were hugely important to medieval Christians because they were both holy and yet still human. Unlike the omnipotent and remote figure of God, medieval Christians saw the saints as beings who cared for individual people and communities and who would potentially intercede on behalf of their supplicants. Thus, every village, every town, every city, and every kingdom had a patron saint who was believed to advocate on its behalf.
Along with the patron saints, the figures of Jesus and Mary became much more important during this period. Saints had served as intermediaries before an almighty and remote deity in the Middle Ages, but the high Church officials tried to advance veneration of Christ and Mary as equally universal but less overwhelming divine figures. Mary in particular represented a positive image of women that had never existed before in Christianity. The growing importance of Mary within Christian practice led to a new focus on charity within the Church, since she was believed to intervene on behalf of supplicants without need of reward.