1. This festival lasts for eight days, starting on the 25th day of Kislev (the third month). It celebrates the victory of the small Maccabee army against the large Greek army of Antiochus, and the Maccabees' recapture and re-purification of the Temple in Jerusalem (c. 168 BC). When they did so, they found only a small amount of oil to light the menorah in the Temple, and it would take a week to make more; miraculously, the oil burned for the full week. To commemorate this, on each night, observers use a 'helper candle' called the shamash to light candles in a menorah (more properly called a chanukiah, as a menorah only has six branches while a chanukiah has nine): one candle (besides the shamash) on the first night, two on the second night, and so on. Furthermore, it is traditional to eat foods fried in oil; in the United States, potato pancakes called latkes are popular; in Israel, fried jelly donuts called sufganiyot are more common. Children play a game with a spinning top called the dreidel, which contains the Hebrew letters that form the initials of a phrase that translates as 'a great miracle happened there' (in Israel, they say 'a great miracle happened here'). Exchanging presents is only a recent tradition developed in the U.S. to make Jewish children feel less left out as their Christian peers get Christmas presents (or, if you are cynical, the tradition was invented by toymakers to sell more toys).

2. Sanskrit for 'The Song of God,' it is a poem found in Book Six of the Hindu epic Mahabharata. Likely formalized in the 1st or 2nd century, the Bhagavad-Gita begins on the eve of a battle, when the prince Arjuna asks his charioteer Krishna (an avatar of Vishnu) about responsibility in dealing with the suffering that the impending battle will cause. Krishna tells Arjuna that humans possess a divine self within a material form, and that Arjuna's duty is to love God and do what is right without thinking of personal gain — some of the main tenets of Hinduism.

3. Celebrated for seven or eight days beginning on the 15th day of Nissan (the seventh month), Passover commemorates the Exodus from Egypt. It is also the ancient Hebrew New Year. On the first day or two days, Jews have a festival dinner called a seder, where they retell the story of the Exodus from a book called a haggadah. Jews are required to abstain from eating or owning leavened bread, and anything made with leaven, for the duration of the festival; matzah (a flat unleavened bread) is eaten instead. On Passover, the Song of Songs is recited. Passover also begins a period of seven weeks called the Omer, a period of semi-mourning that leads into Shavuot.

4. Protestants and Jews assign lower authority to the Apocrypha because it was written between 300 and 100 BC, but Catholics and Orthodox Christians consider the books that make up the Apocrypha to be 'deuterocanonical,' meaning that they are just as important and divinely-inspired as other parts of the Old Testament/Hebrew Bible. 'Apocryphal' in general means 'something outside an accepted canon,' and, in particular, in ancient Greek it meant 'hidden things.' Denominations differ as to which books make up the Apocrypha, but Tobit, Judith, 1 and 2 Maccabees, Wisdom, Sirach (or Ecclesiasticus), and Baruch are almost always included.

5. The founder of Mormonism (many of whose followers now call themselves Latter-Day Saints). He is said to have had a vision in which the angel Moroni directed him to a set of golden plates, from which he claimed to have translated the Book of Mormon, the founding scripture of Mormonism. Based on Ezekiel's vision of a New Jerusalem, he hoped to establish a latter-day Zion in America. Smith initially planned to establish his Zion in Independence, Missouri, but his followers were driven out of the area and moved to Nauvoo, Illinois. When the Nauvoo Expositor criticized him for his teachings on polygamy and other matters, he had the press destroyed and was charged with inciting a riot; while awaiting trial, he was killed by a mob.

6. The founder of the Baha'i faith. He was a follower of the Báb, the founder of a predecessor of Bahá'í called Bábism. At the Garden of Ridvan, Bahá'u'lláh declared himself to be the fulfillment of the Báb's prophecy about 'he whom God shall make manifest.' He was exiled to the outer reaches of the Ottoman Empire for fear that his teachings would cause unrest. He was later imprisoned in Acre (in what is now Israel), where he spent much of his time writing texts such as the Kitab-i-Aqdas (literally, 'the book of laws'). Bahá'u'lláh's other books include The Book of Certitude and Epistle to the Son of the Wolf.

7. Sacred scripture of Zoroastrianism. It consists of five parts: Gathas (poems written by Zoroaster), Visparat (homages to spiritual leaders), Vendidad (legal and medical doctrine), Yashts (hymns to angels and heroes), and Khurda (lesser rituals and hymns). The Gathas may be as old as the 7th century BC, when Zoroaster is thought to have lived, but most of the Avesta was put together by the Sassanid Persian dynasty, between AD 200 and 640. Zoroastrianism centers on the eternal struggle between a good entity (Ahura Mazda, or Ormuzd) and its evil counterpart (Angra Mainyu, or Ahriman); the religion is still practiced by about 120,000 Parsees in Bombay and a few thousand adherents in Iran and Iraq.

8. (1035 - 1099; r.1088 - 1099) Ordered the First Crusade. Ambassadors from Byzantine emperor Alexius Komnenos came to the 1095 Council of Piacenza requesting help in reclaiming the Holy Land from the Seljuk Turks. Urban II responded by calling the Council of Clermont, where he urged a crusade with the phrase 'Deus Vult,' or 'God wills it.' The subsequent First Crusade lasted from 1096 to 1099.

9. One of the Trimurti (the holy trinity of Hindu gods), Vishnu is the Preserver, protecting the world. When needed, Vishnu descends to Earth as an avatar, or incarnation. Nine have appeared so far: Matsya, Kurma (tortoise), Varah (boar), Narasimha (man-lion), Vamana (dwarf), Parashurama, Rama, Krishna, and Buddha. A tenth, Kalki, will appear with a flaming sword to save humans from the darkness. Some cult followers worship Vishnu as Narayana, the primal being. Vishnu has dark blue skin, rides with the eagle Garuna, and sits on the snake Shesha. His symbols are the conch, disc, club, and lotus; his chief wives are Lakshmi and Bhu (the Earth). Kama, the god of love, may be his son.

10. (1475 - 1521; r. 1513 - 1521) A son of Lorenzo de Medici whose papacy included the beginning of the Protestant Reformation. He revived the unpopular sale of indulgences to fund the construction of St. Peter's Basilica. Martin Luther responded by publishing his 95 Theses, which Leo denounced in the papal bull Exsurge Domine. At his coronation, Leo was given a white elephant named Hanno by Manuel I of Portugal; the animal was buried beneath the Vatican after its death.

11. A patriarch common to Judaism, Christianity, and Islam, which are collectively known as the Abrahamic religions. Unlike the other people in this article, Abraham is not regarded as a historical figure in secular studies. He is the subject of the Biblical narrative of the covenant of the pieces, in which God promises that his descendants would inherit the Promised Land of Canaan/Israel; this tradition is the basis for the view that the Jewish people are God's chosen people. In Islam, Abraham (Ibrahim) is considered a major link in the chain of prophets stretching from Adam to Muhammad. In Christianity, he is considered an exemplar of faith because of his willingness to sacrifice his son Isaac at God's command.

12. The founder of modern Jainism. He is regarded as the twenty-fourth tirthankara, or spiritual teacher, who revived and synthesized ancient Jain traditions. His mother, Trishala, is said to have had either fourteen or sixteen auspicious dreams before his birth. In his forties, Mahavira is said to have achieved Kevala Jnana, or infinite knowledge, while meditating under a salah tree. He subsequently taught a number of principles, including ahimsa, the prohibition of violence against living beings of any kind.

13. The third of the Trimurti, Brahma is the Creator. By dropping an egg into the cosmic waters, he hatches a younger form of Brahma that creates other beings. Also the chief priest, he has four heads that each point in a cardinal direction, representing the Four Vedas. Brahma has a fifth head until Shiva plucked it off; as punishment for that act, Shiva is forced to wander as a beggar and carry Brahma's severed skull as a bowl. Brahma's wife is Savitri, who curses him after he lets a cow-maiden stand in for her at an important ritual. Few people worship Brahma, either because of the curse or because he lost a power struggle to Vishnu.

14. An ancient Persian prophet who founded the dualistic religion Zoroastrianism around the 10th century BC. He is said to have had a revelation in which he saw a being who taught him about two primal spirits: a benevolent creator named Ahura Mazda and a malevolent spirit named Angra Mainyu or Ahriman. Zoroaster also learned about the concepts of asha and druj, roughly equivalent to 'truth' and 'falsehood,' and thereafter chose to dedicate his life to promoting asha.

15. A non-Jewish person who wishes to become Jewish may do so with the guidance and approval of a beit din, a Jewish court. Judaism does not seek converts; in fact, it is traditional for a rabbi to refuse a prospective convert three times, and only if they still persist should the rabbi take them as a student. A ger (convert) must study Judaism and explain their motivation to the satisfaction of the beit din, and must immerse in a mikveh (ritual bath). Men must also be circumcised, or if they were already circumcised, a drop of blood must be taken from the penis as a symbolic circumcision (hatafat dam brit). Different Jewish movements have different views on conversion, and some movements will not recognize conversions performed by rabbis from other movements. Conversion may be sought by gentiles wishing to marry a Jewish person, children raised as Jews but who are not technically Jewish (e.g., because their father is Jewish but their mother is not), or simply people who find Judaism attractive for other reasons.

16. Celebrated on the 14th of Adar (the sixth month) and commemorating the victory of the Jews — led by Esther and her cousin Mordechai — against Haman, who tried to destroy the Jews because of his anger at Mordechai. The story, recorded in the Book of Esther (read from a scroll, or megillah), takes place in Shushan, the capital city of the kingdom of the Persian King Ahasuerus (Achashvayrosh). On Purim, it is traditional to dress up, get drunk, give to charity, eat triangular pastries called hamantaschen (meaning 'Haman's ears' or 'Haman's pockets' in German), and exchange gifts (mishloach manot) with friends.

17. (1792 - 1878; r. 1846 - 1878) The longest-reigning pope in history. He reigned during Italian unification and remained a 'prisoner in the Vatican' after the capture of Rome led to the annexation of the Papal States. Afterward, he rejected a Law of Guarantees that sought to define the rights of the Church within the Kingdom of Italy. Pius defined the dogma of the Immaculate Conception in the decree Ineffabilis Deus and established papal infallibility at the First Vatican Council. He released a controversial list of 80 heresies in his Syllabus of Errors.

18. The last and greatest treasure born from the 'churning of the ocean,' Lakshmi is the goddess of prosperity and patron to moneylenders. The epitome of feminine beauty, she sits or stands on a lotus flower and appears in her own avatars alongside Vishnu: Sita to his Rama; Padma the lotus to Vamana the dwarf; Radha (or Rukmini) to Krishna. A form of the mother goddess (Shakti, or Devi), she also represents virtue and honesty.

19. This is a day of mourning for the destruction of the First and Second Temples, as well as a number of other calamities in Jewish history. It is traditional to fast and to keep oneself in a solemn mood. The Book of Lamentations is read in a mournful tone, traditionally while sitting on the floor and with candles as the only lights.

20. Celebrated on the first and second days of the month of Tishrei, Rosh HaShanah marks the beginning of the Jewish civil year. (The beginning of the ecclesiastic year is Pesach.) It is believed that on Rosh HaShanah, people's souls are judged, and God 'temporarily' decides their fate for the coming year. Between Rosh HaShanah and Yom Kippur are the Ten Days of Repentance, when people are given a chance to reflect and repent. On Rosh HaShanah, it is customary to wear white clothes and eat apples with honey for a sweet year, and pomegranates to represent being as fruitful as its many seeds. Other customs include the blowing of the shofar (an instrument made from a ram's horn) and a ceremony called Tashlich, in which Jews throw bread crumbs into running water to symbolize the cleansing of their sins.

21. The basis for ancient Chinese philosophy and religion, the Yijing was created between 1500 and 1000 BC, though legend has it that the dragon-emperor Fuxi derived its eight trigrams from a turtle shell. The trigrams consist of three either broken (yin) or unbroken (yang) lines, and by reading pairs of these trigrams randomly, one could learn about humans, the universe, and the meaning of life. The Qin emperor Shi Huangdi burned most scholarly books, but the Yijing escaped because it was not seen as threatening.

22. Published in 1830 by the founder of the Mormon Church, Joseph Smith. Mormons believe that the prophet Moroni revealed the location of the Book of Mormon to Smith, and then Smith translated it from a 'reformed Egyptian' language. The Book of Mormon is inscribed on thin gold plates, and documents the history of a group of Hebrews who migrated to America around 600 BC. This group divided into two tribes: the Lamanites (ancestors of American Indians), and the highly civilized Nephites, a chosen people instructed by Jesus but killed by the Lamanites around AD 421.

23. Jewish children are given Hebrew names. For boys, the name is formally announced, and blessings are recited, at the brit milah ceremony. For girls, the same is done at a separate event, often (but not necessarily) during a regular synagogue service in the first few weeks of the baby's life. This tradition is primarily observed in more liberal Jewish movements and is not considered religiously required, so practices vary and are evolving. The Hebrew name is used on special occasions such as being called to the Torah and being married, and is typically in the form 'Yitzchak ben Avraham' (Isaac, son of Abraham) or (in egalitarian movements) 'Yitzchak ben Avraham v'Sarah' (Isaac, son of Abraham and Sarah).

24. Celebrated on the 15th of Tishrei, Sukkot commemorates the sukkot (booths) that the Israelites lived in following the Exodus from Egypt; it also celebrates the harvest. Traditionally, Jews build outdoor booths in which they live and eat for seven days. In synagogue, four symbolic species — the palm, a yellow citrus called the etrog, the myrtle, and the willow — are waved in seven directions. Each night, in the sukkah, it is traditional to invite a Biblical figure to be the guest for that night.

25. (1 - 68; r. 30 - 68) The first Bishop of Rome and thus the first pope. Peter was the leader of the twelve apostles; Jesus changed his name from Simon to Peter and declared him the 'rock [on which] I will build my church.' Jesus also bestowed upon him the keys to the kingdom of Heaven and the power to 'bind' and 'loose' in Heaven and on Earth. He was crucified upside-down by Emperor Nero and is the namesake of St. Peter's Basilica in Vatican City.