Most of the myths were based on the ignorance of the people but the really sad part of the vampire legend is that – over the centuries – the Church used these convictions to impose itself and forcefully advance in Europe.
In the Middle Ages the Church officially recognized the existence of vampires but changed certain cases to gain benefit. And by preaching about it, they transformed the vampire from a folkloric creature [with pagan roots] into a monster enslaved by the Devil. The vampire was used to enforce the basic principles related to redemption and the after-life. Based on the concept of the Last Supper, “the body and blood” became “the flesh and the blood”.
The “hordes” of easily influenced peasants gathered in churches to listen to the lies of the priests meant to replenish the funds of the churches [they didn`t pay taxes of any kind for the “donations” they would receive to offer protection against vampires and witches].
The Church pretended that malefic creatures could be stopped only by the divine power of God. And the more evil they made the vampires, the more they got for that supposed protection.
The tragic part is that thousands of women were burnt at the stake because they were accused of witchcraft by lunatics that hide after the sign of the cross. Fanatic mobs would gather in cemeteries to chop up and mutilate corpses, under the pretense that they were vampires that needed to be eradicated.
In 1489, the Church issued a document entitled “Malleus Maleficarum” describing ways to destroy “evil creatures”. Many fell victims to this documents for they were tortured and executed for no real reason.

Two centuries after, in 1645, the priests were still taking pleasure in instilling fear in the people.
This time, the vampire was the result of excommunication. Because the body wouldn`t rot, the soul couldn`t leave the earthly plain.
Ironically, the lack of decomposition symptoms was also a sign of holiness. The supposed difference was made by the smell of the corpse – a sanctified body smelled “nice”.
In the end it was the priests that decided, probably based on the donations made by the family, be it in furniture, gold or even cattle given away for the benefit of the religious community.
NOTE: The alleged vampires were buried with garlic in their mouth!
Another of the numerous contradictions is that the Church basically had the power to create vampires because a priest could keep a soul trapped on this plain by excommunicating the person [denial of redemption].
It was within their power to grant pardon, therefore to destroy the vampires.
NOTE: Then why keep those grotesque rituals if a simple holy ceremony would have sufficed?

A couple of cases found in religious records:
1. In the 10th century, it is believed that the Archbishop of Bremen excommunicated a gang of pirates. Years after, when the bodies were discovered it seams that they needed special masses because the bodies weren`t rotting and the passing to the after-life was impossible.
2. William of Newburgh presented the case of a man who returned from the grave to torment his widow, but since the family was of wealth and they had purchased a great deal of pardons, the bishop of the region send a messenger with “holy writings” to save the man`s soul. Once the pieces of paper were placed in the coffin the nocturnal visits ceased.