Today is Hallowe’en. In medieval times that evening before All Saints was used to scare away any bad spirits so that Christians could celebrate those who had demonstrated in their life great faith (All Saints), and then the next day, November 2, all others who had died in God’s favour (All Souls).

How do you scare bad spirits? Medieval superstition said by dressing up as even worse looking ghosts and make a lot of noise. The same was done in Europe at Carnival, the days before Ash Wednesday, when Lent begins and at New Year’s Eve.

Besides superstition, October 31 has its own place in Church history for a different reason. Exactly 509 years ago, on October 31, 1517, an Augustine monk and theology professor, Martin Luther, protested with 95 theses, which he nailed to the door of the castle church, against certain Church practices that had entered doctrine during the Dark Ages like selling indulgences. So yes, in a way Luther tried to get rid of some “bad spirits” that Hallowe'en.

It was the time of Renaissance and philosophical humanism, focusing on the human nature in science and art, researching antique sources and discovering in that process new understandings.

The invention of printing with moveable letters in the mid 1400s made it possible to spread new knowledge and ideas fast across Europe. Based on old Greek theories and improving astronomy studies more and more people came to understand that the Earth is a sphere.

In 1492 Martin Behaim produced the first modern globe and at the same time Columbus discovered the Americas. New horizons opened up, literally. At the new founded universities through out Europe theologians rediscovered the value of the original Hebrew (Old Testament) and Greek (New Testament) Bible texts instead of just using the Church approved fourth-century Vulgate, a Latin translation of the Greek New Testament and a Greek translation of the Old Testament, the Septuagint.

Luther, together with language scholar Philip Melanchton, was at the University of Wittenberg in Saxony. Luther had studied in particular the Letters of Paul. He had found that salvation is offered to believers not as a reward for good deeds, but as a free gift (by grace alone) as explained e.g. in Romans chapters 3 and 11 and Ephesians 2:8-9 (NIV): “For it is by grace you have been saved, through faith — and this is not from yourselves, it is the gift of God — not by works, so that no one can boast.”

It also was the time when the Pope in Rome wanted to build St Peter’s, and the Archbishop of Mainz needed money to pay the bribes for his third bishopric. They needed a fundraiser.

So the Church launched an indulgence sell. Medieval doctrine taught that baptised and believing Christians would be spared hell, however, if they had a negative balance, meaning more sins than good works, they would have to be purged from that sin by fire like precious metals.

Thus the Church invented purgatory, and buying indulgence would free Christians faster. The sales slogan was: “As soon as the coin in the coffer rings, the soul from purgatory springs”. People could buy good deeds performed before by the saints, who supposedly had their surplus of good deeds left to the Church.

Luther challenged doctrine based only on tradition and insisted on the biblical (through scripture alone) understanding of salvation through the sacrifice of Christ (through Christ alone), which is offered to all who believe and trust this promise (by faith alone).

What a fear relieving new freedom!

Till today many believers have experienced this new freedom. The God of love is not vengeful, but has compassion with all who are called to be his children. God does not expect us to be perfect or become saints by our own works and deeds, but we are good enough.

The fear of punishment in a church-invented purgatory vanished. The Bible does not talk about purgatory, it was an invention of the medieval Church to gain power and control over the people.

Hallowe'en 1517 became known as the beginning of the Protestant Reformation, and Protestant Churches around the world remember that day as Reformation Day.

Reformation is all about freedom. It changed the way of thinking in the western world for ever. Before the Reformation, the Roman Church had almost immeasurable power over people, science, and even rulers. There were threats of excommunication leading to eternal hell and there was the witch-hunt.

The fear of eternal torture made even kings give in when in conflict with Rome. Superstitious ideas like witchcraft, ghosts and spirits were spread to induce fear, which only the Church, like the Inquisition, could effectively fight.

Today we know the witch-hunt of the medieval times was all about power of a male-dominated Church, but back then people were scared to death of bad spirits and witches.

I am sometimes amused when I see how even secular folks and atheists love to run to horror movies to get a spine-chilling feeling. There is nothing like a little supernatural.

Imagine the freedom from fear the Reformation provided. While Rome tried to use its old powers to stop this new thinking, the times had changed. Henry VIII, who first was aggressively against the ideas of the Reformation (the Pope had honoured him for that with the title: Defender of the Faith, a title British monarchs still hold), soon separated from Rome as well, though for very personal reasons.

Many regions in Germany, France, Switzerland, Austria, Czechia, Slovakia, Scotland and the Scandinavian countries turned to Protestantism, often with the support of the rulers, sometimes in defiance to them.

Truth could no longer be suppressed, the Bible was translated into modern languages, and in the long run it actually changed the Roman Church as well. Society changed as well. Ideas like modern democracy and individual freedom were only possible because the new freedom of the Reformation.

Luther had written a famous essay about The Freedom of a Christian, in which he has the paradoxically sounding thesis: “A Christian is a perfectly free lord of all, subject to none, and a Christian is a perfectly dutiful servant of all, subject to all.”

The first half describes the new freedom of the Gospel. In the inner spiritual person, the soul is justified, saved, and freed completely by faith alone in the Word of God, without needing any religious works, rituals, or ceremonies. Salvation cannot be bought for money either. God’s blessings and love don’t depend on what you do or give.

The second half means that at the same time the believer is bound by love to serve, help, and care for their neighbour in daily life. A believer makes himself subject to all because he is free.

So it is not only freedom from, but also freedom to, to do what is right and listen to one’s conscience. Once a Christian understands how much God loves us, one will understand that God has the same love for one’s neighbour, and thus we are to love our neighbour as ourselves as well. It is our loving response to our salvation that leads to sanctification, to fruit of the faith.

This freedom allows us also to continue with traditions like Hallowe'en, as we know that haunted houses, witches, ghosts and zombies are just products of human fantasy, and nowadays are there to have some fun. At the same time, trick or treating should be done in a way all can find funny so no one will be hurt.

• Karsten Decker is an ordained Lutheran pastor and novelist from Germany who has lived and worked in Bermuda since 2001. At the moment he helps the Centenary Methodist Church at Collectors Hill as pulpit supply.