RELIGION is a collection of different beliefs, customs, nationalities, belief of having an eternal connection with the god (the supreme power) 

Different religions are practiced all around the world. Every religion has its own unique religious practices, beliefs, customs, symbols. Some common religions sre Hinduism, Islamic, Christianity, Jainism, Buddhism and many more. According to the data collected they are nearly 10000 religions present in worldwide. The different religions include different practices of diety, festivals, feasts, food, prayer, marrital rituals, funerary rituals, music, art and many more. More than 80% of the world's population is comprised of Christianity, Islam, Hinduism, Buddhism and many more folk religions. Different religions also comprises their respective holy books like vedas, purans some of them popularly include the Bible, the Quran, Ramayana, Mahabharata etc. 

Many religions also include many mythologies which people believe and follow blindly. And due to which many people take advantage of other people or community in the name of god and they earn a chance to decieve them which is strictly not a good practice as it shows you are not truly dedicated to your supreme power or to humanity. Not all believe believe in their religion or god many are a true non believer of god and such section of society are called as Atheists. And the peoole who have a strong belief in god or supreme power are called as theists. 

India is a secular county and many festivals, religions, rituals, customs are practiced here. In our country every state has it's own popular festivals including the famous Rath Yatra of lord Jagannath at puri, ganesh chaturthi , diwali, dussehra at several parts of India.  The most popular language used in the Hindu and many more religious texts is Sanskirit or Prakrit.

Through the study of those religious texts it was concluded that these do not come in equilibrium with the those of western culture. And to make to them more readable and reachable among different sections of society these texts were converted to Hindi or English. When India was under the colonial rule under the Britishers English language was taught to people and many of them were converted into Christianity. The world Hindu specially signifies being an Indian. Likewise many countries follow their different religions and as per my knowledge i think Japan is a country where no religion is practiced also due to colonisation of many countries by different other countries have also forced the colonised country to practice their respective religion which in turn gave them an exposure to western culture and religions.