Creationists, including those of Answers in Genesis and Institute of Creation Research, constantly claim that the roots of young earth creationism can be traced to ancient Judaism writings such as in the writings of Abraham Ibn Ezra (c. 1089–1164), a Jewish astrologer and Rabbi, and Josephus (c. 37 – c. 100), a famed Jewish historian and that this was the original "viewpoint" of the early church fathers that persisted until modern times. This is false. A lie made up to cover up the fact that the dogma of young earth creationism is of modern invention. The truth of the matter is that even though Jewish Scholars did believed that the earth is thousands of years old, none of them really believe that the earth is 6,000 years old (4,000 years after Creation and before Christ + 2,000 years after Christ was born according to the order of events and genealogies of the Bible, never mind them being out of order and filled with gaps in between). They believed it to be far more older than that (Cherry, 2006).
The 6,000 year lie touted by the creationists is based on a conclusion put on by the likes of Archbishop James Usher who concluded that the earth was about 6,000 years old after attempting to calculate the age of the earth by adding up all the dates and the genealogies of the Hebrew Bible and other supplemental texts together and coming up with the concept of the earth being created on October 24, 4004 BC as a result. He wasn't the only one who made such an attempt, though. Other scholars made similar attempts to calculate the age of the earth using Biblical texts and come up with different conclusions ranging from the earth being either between 3,000-2,000 years old or between 7,000 and 10,000 years old.
At those times, science, as we know of, was completely unheard of. No one, not even the scholars who calculated the earth's age through religious texts, knew for sure how old the Earth was. Much of their guesses about the planet's age and how long "a day" was when God created the universe based on II Peter 3:8 is about as good as they can get. Also, early church leaders, including Saint Augustine, begin questioning the authenticity of the Genesis account of creation and the Flood and concludes that there is no way, no how can the world be created in 6-24 hour sequences and that either the Flood only occurred in a regional area or didn't really happened at all. Therefore the stories are to be treated as allegories made to teach people lessons about God and His attributes.
It was in the 18th and 19th centuries when people, Christian and Non-Christians alike, began to uncover evidence that tells them that the planet is in fact much, much older than anyone can ever imagined, pointing to the fact that the planet is amazingly billions of years old. But not everyone is convinced of this.
The young earth creationism cult as we know of is only about 145 years old and its roots can only be traced to the teachings of the Seventh Day Advantist. According to Ronald L. Numbers' The Creationists: The Evolution of Scientific Creationism (University of California Press, 1993) and its updated version The Creationists: From Scientific Creationism to Intelligent Design (Harvard University Press; Expanded edition, 2006), The roots of young earth creationism can all be traced to a one religious cult— The Seventh Day Adventist. This cult invented the young earth dogma (Even Henry Morris (1918-2006), the so-called "father of the modern creationism movement" acknowledged this.) in direct response to Charles Darwin's so-called "dangerous idea" as told in his book, On The Origins of Species Through Natural Selection, published in 1859. While Christians observe the Sabbath Day as a day of worship on Sunday, this religious sect observes their Sabbath on Saturday in honor of the Creation Week according to their interpretations of Genesis 1 of the Bible. When they heard about Charles Darwin's revolutionary new idea that theorized that all life evolves over time through Natural Selection, they became troubled by it. This new teaching did not fit into their religious preconceptions at least until their mistress and founder of the Seventh Day Adventist Movement, Ellen G. White, (1827-1915) a self-proclaimed prophetess and a cult leader, claimed, one day in 1864, in one of her writings, that she allegedly had seen a vision from God who showed her how He created the universe and the earth in a 6 day-24 hour period, and that the fossils were all the result of plants and animals that had perished during the Great Flood of Noah. To her disciples, this alleged vision solves the whole problem and they began to take her visions and her teachings to heart.
One of Ellen's disciples, George McCready Price (1870-1963) became so hooked on this idea that he began to endorse it and distribute magazines about this new form of creationism to many people in order to win converts. Then in 1923, Price published a book called The New Geology which told his ideas about Earth being 6,000 years old, created in 6 literal 24 hour day periods, and which was later covered with the great Flood of Noah, which destroyed everything and turned all of the plants and animals into fossils.
Scientists and other people, who knew better than to believe in these faulty teachings gave them little or no credence and just simply laugh it all off. But the Christian Southern Baptists group loved them and took these teachings to heart. One of them was a Southern Baptist Preacher named Henry Morris who became one of Price's most loyal disciples. He liked his teachings so much that in 1960 he paired up with another young earth believer named John Whitcomb to write and publish their first young earth manifesto entitled The Genesis Flood, a book filled with contents most heavily borrowed from The New Geology, the world's first young earth manifesto. This book became a sensation among many southern baptist groups who hold it in high regard and used it to start the modern creationism movement that continues to this very day. Over the years, many organizations sprang up to advocate this unsupportable dogma, such as the Institute for Creation Research, 'Answers' in Genesis, Creation Ministries International, and Creation Science Evangelism, just to name a few.
What these organizations advocate is a threat to intelligence as well as a threat to the Christian Faith and are known to give many a hapless Christian a false notion that says science, especially evolution, is nothing but lies made up by Charles Darwin through Satan. They try to scare people into not accepting evolution, claiming that all of the supporters of evolution are in the League of Satan, and the YEC's own interpretations of the Bible are the interpretation representative of Christianity that is 100% historically and scientifically true, literal, and accurate, while it's in fact not. And if they don't accept their lies as the Truth of God's Word, they will find themselves burning in Hell for all eternity.
Many a hapless Christian buy into this dogma not knowing that this is anything but a Christian representation and contains nothing but malicious slander, hate and fear mongering, and gossip against those who oppose their views, trickery, hostility, emotional appeals, hypocrisy, mudslinging, bigotry, bickering, money extortion, hypocrisy, falsehoods, stupid lies, spiritual blindness, the desire to hurt, threat, and traumatize, ignorance, fallacies, self-righteousness, empty threats of Hell, and man made teachings imposed as if they were established by God. This is not the worst of it. Creationists who support this dogma are indoctrinating people, especially children, into believing in all sorts of idiotic claims of the Earth being 6,000 years old (meaning it was created at the time of the Egyptian Predynastic Period and the building of Stonehenge to name a few of the events that took place about 6,000 years ago during the alleged time of Creation, the earth was once entirely covered with the Great flood of Noah 4,500 years ago in 2495 BC/BCE (at the same time as the construction of the Pyramids of Egypt in Giza as well as other events.), evolution is to be blamed for all the world's evils, dinosaurs once lived with man, there are no transitional (in between) forms (either living and dead), scientists are involved in a satanic, secret conspiracy, Dating Methods cannot be trusted, light speed is slowing down, and so on.
All of this is nothing but senseless nonsense, especially from a real Christian viewpoint. Such teaching like that can only drive people away from churches instead of winning souls to Heaven.
Cherry, S (2006). Crisis management via Bilbical Interpretation: Fundamentalism, Modern Orthodoxy, and Genesis in Jewish Tradition and the Challenge of Darwinism (Cantor, G Swetlitz, M, editors. University of Chicago Press. ISBN 978-0226092775.
The Creationists: The Evolution of Scientific Creationism and The Creationists: From Scientific Creationism to Intelligent Design by Ronald L. Numbers