The Siberian Shaman
Humanity's original religion was probably Animism. Animists believe that all things living or dead have spirits, even inanimate objects like rocks, trees, rivers and motorcycles. Animals hunted and killed for food, or trees cut down for construction projects have spirits too. It is OK to to kill the deer or cut down the oak but their spirits must be treated with proper respect. The Redneck has been bitten, burned, tripped, and smacked by just about every inanimate object or living thing he failed to treat with respect. Animism remains the religion of choice in remote inhospitable environments from the high arctic to steaming jungles and arid deserts, places where a good deal of respect for the things around you are needed for survival. You might be a closet animist if you swear at hammers that hit your thumb, or if you gave your car a name other than the manufacturer or registry office supplied one.
According to Wikipedia, if asked for their religion, half the world's population will say they follow one of these five, Christianity (2.4 Billion) Islam (1.9 B) Hinduism (1.2 B) and Buddhism, trailing with 0.5 B. Religions don't stop there, there is still a wide variety to choose from.
Many religions have angry gods. When gods are angry bad shit happens, or bad shit happened, so gods must be angry. Angry gods may need to be appeased by sacrifices, including the kids, so that rain falls when it should, volcanos don't erupt, or some other catastrophe needs averting. Angry gods require followers to perform various kinds of penance, such as fasting, flagellation or going to war to smite your god's enemies.
Christianity is headed by a wrathful sky cop, a holy spirit, and an invisible friend who loves children. Confusingly they are all the same but separate at the same time. The sky cop sees everything, if something or someone displeases him he may send an earthquake or flood to punish offenders or he may just keep score, because once you are dead, the rest of eternity is available for meting out reward and punishment. The holy spirit can enter humans causing them to behave in entertaining ways, such as yelling, speaking unknown languages, and general frothing about. The invisible friend, Jesus, somehow the son of god and and god at the same time, unlike his dad, ie, his wrathful self, can forgive all your sins if you say you are sorry. Jesus is often portrayed is a shepherd, which should be a warning, what happens to all those little lambs when the shepherd brings them in from the fields?
Christianity and Islam are actually Judaism lite and Judaism 2.0 respectively. Judaism was founded by Abraham and his son Isaac. Judaism was reserved for the descendants of Isaac, so it is unlikely you will ever answer the door to a Jewish missionary. Ishmael, Isaacs half brother was invited to leave Abraham and Isaac and become an Arab. One of Ishmael's descendants, Muhammad, converted Judaism to Islam. Islam will accept you even if you are not descended from Ishmael, but there is a catch, the penalty for failure to obey Allah's many commandments is harsh. Islam and Judaism restrict themselves to just one god with one kind of existence, vengeant sky cop. The difference appears to be that Judaism's God only punishes the descendants of Isaac, whereas Allah only punishes those who do not believe in him. Isaac and Ishmael's descendants are currently trying to kill each other. Christians are not descended from Abraham, but that hasn't stopped them from trying to kill Isaac and Ishmael's descendants either.
Hindus have over a million gods, which seems excessive.
Buddhism, which according to the Buddha isn't a religion but nobody told his followers who pray to him anyway. The goal of Buddhism is to follow the eight fold path. If you stray from the eight fold path and die, you will get a do over. You will keep getting sent back like some cosmic video gamer who can't turn off their console until they get it right. Then you won't have to come back anymore, you will have achieved Nirvana and Buddha status. If you really screw up your eight fold path, you could be sent back as an earthworm or a politician.
The Redneck was raised to be a Christian, but eventually came to the conclusion that unlike Genesis chapter 1 verse 27, Man and woman were not created in God's image, God was created in Man's image. I think the Animists probably got it right.