Tonight, HinduA follower of Hinduism, the third-largest religion in the world. Roughly 95% of Hindus live in India. communities will be lighting candles and letting off fireworks. Meanwhile, in Christian countries, children will be circling their neighbourhoods with torches and lanterns, dressed like witches, wizards, vampires and ghosts.

Two major festivals are taking place this evening. The first is Halloween, when people remember the dead and all things supernatural. The second is Diwali, the Hindu festival of lights, when the victory of good over evil is celebrated.

In America, around 70% of the population plans to take part in Halloween.¹ In total, 37 countries mark this festival.² Meanwhile, around one billion Hindus celebrate Diwali worldwide.³

Not everyone who celebrates these festivals is religious. Nonetheless, ideas like remembering the dead or finding hope in darkness matter to believers and non-believers alike.

In many countries, there are signs that religion is in decline. One recent survey suggested that most of Americans are unsure about the existence of God.⁴ Meanwhile, in Western Europe, the number of people who never engage with religion is at record high levels.⁵

Many scientists think people should focus on the material world - things you can see, touch and measure. Religions often have old-fashioned ideas about the role of women and the treatment of gay people. They can also fuel hatred between different groups and even inspire violence.

However, other thinkers argue that religious belief makes people happier and healthier. For instance, people who regularly attend church are widely believed to be at lower risk of depression, anxiety, and suicide, as well as cardiovascularRelating to the heart and blood vessels. disease and death from cancer.

This may be because religion gives people a sense of community or helps them cope with crises. Whatever the reason, the benefit is similar to avoiding other "major health risks - like smoking," according to respected researcher Dr Laura Wallace.⁶

Of course, nobody is celebrating Halloween or Diwali for health reasons. But their popularity suggests that people still care about non-material matters, whether this means fears about the past or hopes for the future. And the fact that believers and doubters can both take part makes them perfect festivals for the modern world.

Do we all need a spiritual life?

Yes: The material world is made up of things: it cannot provide meaning, morality, or comfort in times of crisis. People need the spiritual realm, whether or not they believe.

No: Nobody can prove that the spiritual realm even exists. Reason, science and a practical approach to life will bring much more happiness than religion.

Or... Many people believe something but no longer feel comfortable with organised religion. Festivals like Halloween or Diwali let them explore spiritual questions in their own way.

Hindu - A follower of Hinduism, the third-largest religion in the world. Roughly 95% of Hindus live in India.

Cardiovascular - Relating to the heart and blood vessels.