Today's Halloween customs are thought to have been influenced by Christian dogma and practices derived from it.
Halloween is the evening before the Christian holy days of All Hallows' Day (also known as All Saints' or Hallowmas) on 1 November and All Souls' Day on 2 November, thus giving the holiday on 31 October the full name of All Hallows' Eve (meaning the evening before All Hallows' Day).
Since the time of the early Church, major feasts in Christianity (such as Christmas, Easter and Pentecost) had vigils that began the night before, as did the feast of All Hallows'.
These three days are collectively called Allhallowtide and are a time for honoring the saints and praying for the recently departed souls who have yet to reach Heaven.
Commemorations of all saints and martyrs were held by several churches on various dates, mostly in springtime.
In 609, Pope Boniface IV re-dedicated the Pantheon in Rome to "St Mary and all martyrs" on 13 May. This was the same date as Lemuria, an ancient Roman festival of the dead, and the same date as the commemoration of all saints in Edessa in the time of Ephrem.

The feast of All Hallows', on its current date in the Western Church, may be traced to Pope Gregory III's (731–741) founding of an oratory in St Peter's for the relics "of the holy apostles and of all saints, martyrs and confessors".
In 835, All Hallows' Day was officially switched to 1 November, the same date as Samhain, at the behest of Pope Gregory IV.
Some suggest this was due to Celtic influence, while others suggest it was a Germanic idea, although it is claimed that both Germanic and Celtic-speaking peoples commemorated the dead at the beginning of winter.
They may have seen it as the most fitting time to do so, as it is a time of 'dying' in nature.
It is also suggested that the change was made on the "practical grounds that Rome in summer could not accommodate the great number of pilgrims who flocked to it", and perhaps because of public health considerations regarding Roman Fever – a disease that claimed a number of lives during the sultry summers of the region.

By the end of the 12th century they had become holy days of obligation across Europe and involved such traditions as ringing church bells for the souls in purgatory.
In addition, "it was customary for criers dressed in black to parade the streets, ringing a bell of mournful sound and calling on all good Christians to remember the poor souls." "
Souling", the custom of baking and sharing soul cakes for all christened souls, has been suggested as the origin of trick-or-treating.
The custom dates back at least as far as the 15th century and was found in parts of England, Flanders, Germany and Austria.
Groups of poor people, often children, would go door-to-door during Allhallowtide, collecting soul cakes, in exchange for praying for the dead, especially the souls of the givers' friends and relatives.
Soul cakes would also be offered for the souls themselves to eat, or the 'soulers' would act as their representatives.
As with the Lenten tradition of hot cross buns, Allhallowtide soul cakes were often marked with a cross, indicating that they were baked as alms.
Shakespeare mentions souling in his comedy The Two Gentlemen of Verona (1593).
On the custom of wearing costumes, Christian minister Prince Sorie Conteh wrote: "It was traditionally believed that the souls of the departed wandered the earth until All Saints' Day, and All Hallows' Eve provided one last chance for the dead to gain vengeance on their enemies before moving to the next world.
In order to avoid being recognized by any soul that might be seeking such vengeance, people would don masks or costumes to disguise their identities".

It is claimed that in the Middle Ages, churches that were too poor to display the relics of martyred saints at Allhallowtide let parishioners dress up as saints instead.
Some Christians continue to observe this custom at Halloween today.
Lesley Bannatyne believes this could have been a Christianization of an earlier pagan custom.
While souling, Christians would carry with them
Today's Halloween customs are thought to have been influenced by Christian dogma and practices derived from it. Halloween is the evening before the Christian holy days of All Hallows' Day (also known as All Saints' or Hallowmas) on 1 November and All Souls' Day on 2 November, thus giving the holiday on 31 October the full name of All Hallows' Eve (meaning the evening before All Hallows' Day). Since the time of the early Church, major feasts in Christianity (such as Christmas, Easter and Pentecost) had vigils that began the night before, as did the feast of All Hallows'. These three days are collectively called Allhallowtide and are a time for honoring the saints and praying for the recently departed souls who have yet to reach Heaven. Commemorations of all saints and martyrs were held by several churches on various dates, mostly in springtime. In 609, Pope Boniface IV re-dedicated the Pantheon in Rome to "St Mary and all martyrs" on 13 May. This was the same date as Lemuria, an ancient Roman festival of the dead, and the same date as the commemoration of all saints in Edessa in the time of Ephrem.
The feast of All Hallows', on its current date in the Western Church, may be traced to Pope Gregory III's (731–741) founding of an oratory in St Peter's for the relics "of the holy apostles and of all saints, martyrs and confessors". In 835, All Hallows' Day was officially switched to 1 November, the same date as Samhain, at the behest of Pope Gregory IV. Some suggest this was due to Celtic influence, while others suggest it was a Germanic idea, although it is claimed that both Germanic and Celtic-speaking peoples commemorated the dead at the beginning of winter. They may have seen it as the most fitting time to do so, as it is a time of 'dying' in nature. It is also suggested that the change was made on the "practical grounds that Rome in summer could not accommodate the great number of pilgrims who flocked to it", and perhaps because of public health considerations regarding Roman Fever – a disease that claimed a number of lives during the sultry summers of the region.
By the end of the 12th century they had become holy days of obligation across Europe and involved such traditions as ringing church bells for the souls in purgatory. In addition, "it was customary for criers dressed in black to parade the streets, ringing a bell of mournful sound and calling on all good Christians to remember the poor souls." "Souling", the custom of baking and sharing soul cakes for all christened souls, has been suggested as the origin of trick-or-treating. The custom dates back at least as far as the 15th century and was found in parts of England, Flanders, Germany and Austria. Groups of poor people, often children, would go door-to-door during Allhallowtide, collecting soul cakes, in exchange for praying for the dead, especially the souls of the givers' friends and relatives. Soul cakes would also be offered for the souls themselves to eat, or the 'soulers' would act as their representatives. As with the Lenten tradition of hot cross buns, Allhallowtide soul cakes were often marked with a cross, indicating that they were baked as alms. Shakespeare mentions souling in his comedy The Two Gentlemen of Verona (1593). On the custom of wearing costumes, Christian minister Prince Sorie Conteh wrote: "It was traditionally believed that the souls of the departed wandered the earth until All Saints' Day, and All Hallows' Eve provided one last chance for the dead to gain vengeance on their enemies before moving to the next world. In order to avoid being recognized by any soul that might be seeking such vengeance, people would don masks or costumes to disguise their identities".
It is claimed that in the Middle Ages, churches that were too poor to display the relics of martyred saints at Allhallowtide let parishioners dress up as saints instead. Some Christians continue to observe this custom at Halloween today. Lesley Bannatyne believes this could have been a Christianization of an earlier pagan custom. While souling, Christians would carry with them 
Halloween