Before Christ, the world was essentially pagan except the Jews. The Jews never tried to erase or hijack other religious belief systems because they never, as well, tried to convert anyone into their faith. And if you still haven't learned about it, Judaism, as far as the scriptures are concerned, stops about 400 years before Christ. They reject a lot of books in the Bible even those written in their time (Apocrypha and Deuterocanonical books) that they thought were not inspired. They only went by books that were authored by Moses and other main prophets. And those ancient pagan religions that you think were appropriated by the Jews had survived and coexisted with Judaism for millenias until Christianity became the dominant religion. And that is not just because of forceful conversions of pagans into Christianity. It is because of the unstoppable spread of Christianity that the Roman Empire, even after having slaughtered thousands of Christians for three hundred years, decided to adopt it as their official religion. Pagans were more likely to convert into Christianity (due to the demonstration of faith of Christians through martyrdom) than Christians converting to paganism. Christians would rather die than renounce their faith. The pagans were not steadfast with their faith. They're willing to convert even for trivial reasons. The number of Christians only grew more despite the persecution and it became a big problem for the Romans. The Romans had NO other choice but to make Christianity the official religion of the empire and everyone else had to convert except the Jews. Even amidst persecution the Jews continued to practice their own faith and rejected Christianity. And even other pagan religions (Norse religion for example) which were never touched by the Romans died out as well. The end of paganism was inevitable regardless.
And it always amazes me whenever Judaism and Christianity are accused of stealing from paganism while I've never heard that any religions stole from the Judaism/Christianity or other religions. Many religions include stories of a flood, a God-man, and stories of resurrection from the dead. Even the Navajos which was in the Americas and never had contact with the Old World had such. The fact is, the knowledge of these shared beliefs were known by many cultures for millenias. Nearly all religions have a flood story simply because there was one. The ancient Egyptian, Hindu, and other pagan religiosn had a saviour figure (and closely resemble that of Christianity) because they were prophecies of Jesus.
It would never hurt to see countless sources explaining how Judaism/Christianity/Islam are essentially rehashed versions of religions much older than them. The reason it came to light only recently is that the pieces of evidence were hidden for a long time that were it not for the latest archeological discoveries, we would never have known. Moreover, the task is made more complicated by the fact that even if we have the evidence, say in the form of cuneiform tablets, for example, it would take a certain time before we are able to decipher their meaning. But now we know that the tales of creation, the flood, much of the content of the Old Testament and New Testament, the Nazarene, etc., etc., were derived from much older sources. The question then arises: why did they lie hidden for a long time? Because, the Israelites, as well as many conquering powers back in the time, had the nasty habit of destroying the historical records, literature, and everything else of the conquered, literally seeking to vanquish into total obliteration the existence—and evidence thereof—of the losing people.
It is irrelevant how the three religions finally came up with official dogma, throwing away unacceptable materials that do not agree with the consistency of the total whole. If anything, it supports the truth that the final creed is not unlike any edited Marvel/DC self-consistent hero universe. As Moses is largely a derivative of either Horus or Sargon, we now know that there is no Moses as the bible dutifully describes him. And many scientists would agree. The biblical materials that we ascribe to a single person known as Moses are beautiful ensemble of edited scripts by great Jewish leaders who were watching closely over the flock.
The only reason why Christianity became the dominant religion is because the Roman Empire adopted it. Great organizers and utilitarians that the Romans were, they saw in the Old Testament, which lends itself greatly to a marauding interpretation, mighty opportunity to expand their territories and influence, while the New Testament they saw as a formidable sedative to keep the subjugated people meek and manageable—that is, as a way for subdued nations and classes all over the face of the earth to have some measure of pittance for their miserable existence and make them docile and submissive for later conditionings. The Old Testament they viewed as the master credo, the New Testament as the subject gospel, exhorting the conquered subjects not to seek earthly contentment in the current life anymore, but to seek it in the next one instead. Afterall, not all people could be masters at the same time, could they? If the first principle, that of physical conquest, failed them in their search for world dominion, then surely the second—spiritual conscription—should secure it for eternity. For the Romans who had been looking for a way to master the world ahead of Alexander the Great's vision—of one world system, if not government—Christianity was heaven-sent elixir indeed in that direction, a twofold approach whose probability of failure was almost close to nil given the immense resources of the Empire of that time.
With the Romans now backing Christianity full force, what's to stop the religion then? Some people they tried to convert by peaceful means, but tellingly, much more were tested and put to the sword if they tried to stick to their old faiths. The saddest day for multiculturalists, or whatever they would have called them then. In any case, thus started the destruction of other cultural and religious icons, written materials, etc., that did not go well with the Christian fathers at the time. Does the Temple of Artemis sound familiar to anybody? It was the top of the ancient 7 wonders of the world back then, but Christian fanatics did not show the slightest hesitation to burn it to the ground. Who lost? We, the people of posterity and the others of the future.
"And it always amazes me whenever Judaism and Christianity are accused of stealing from paganism while I've never heard that any religions stole from the Judaism/Christianity or other religions." Exactly. The reason again?
Because there was/is nothing to steal 
As I said, Judaism/Christianity/Islam did not even bother to add to any existing fairy tales of the time, merely content to use what was readily available to further their own agendas. When we touch on this issue, we must not forget that these stories
predated the Jewish versions by thousands of years. For example, what we know as Noah was really ZIUSUDRA aka UTNAPISHTIM of the Atrahasis Epic, a Sumerian/Babylonian/Akkadian epic that was recounted thousands of years before the Jews came up with the bright idea of replacing the name with their local version, Noah. Heck, even anime lovers are familiar with Gilgamesh, another much, much earlier recounting of the flood story.
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Most of those conspiracy theories about them are actually negative propagandas spread by the Nazis throughout Germany to convince people that the Jews were to blame for Germany's economic depression. Unfortunately stupid rumours like these tend to stick around in the minds of, um, pardon me for the term, idiots.
Although I do not agree with the Hitler solution, I do see where
some of the accusations against the Jews were coming from: mostly, if pertains to how the Jews have come to hold the whole economy of Europe by the throat by holding many royal houses indebted to Jewish bankers and financiers, largely by financing endless wars and extorting stratospheric interest afterwards. The irony, however, is that many Jews also made tremendous profits from the deaths of their fellow Jews, financing even Hitler's own atrocities at the height of World War 2 against their very own people, though hidden through business partnerships with American and other European concerns of the time.
The truth of the matter is that many ordinary Jews paid the price for the success of a few Jewish families in the finance and business sector, victims of the success of their more cunning brothers who shrewdly manipulated the bloodlust of the warring royalties of Europe at the time.
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Do you even know what the Land of Israel was like before the Jews returned there in the 19th century? A barren wasteland. Israel was mostly hot desert not suitable for habitation until the Jews due to their ingenuity cultivated the land and made it bloom. The truth is that the majority of Arabs in Israel have immigrated to it only during the 20th centuries due to the economic boom in pursue of a better life.
That land belonged to no one after the fall of the Ottomans, and there was no government there yet because the people were not yet ready, and so it was the UK that was assigned by the League of Nations to take care of it. It was understood from the beginning that Israel would be the Jewish homeland. Yes, they acquired most of the depopulated areas and cultivated the land so it rightfully belongs to them. Lebanon was supposed to be the homeland of Christian Arabs. And Arab Muslims (there was even no distinction between Palestinians and Jordanians; they are just one ethnicity.) were supposed to be in Jordan but the Arabs did not follow what was initially planned like they always do and launched an Arab movement (started by whom? surprise, it was an ally by Hitler, his name was Mohammad Amin al Husayni) claiming all of the land and wanting the Jews be removed from the region hence the root of this conflict. The Jews were gracious enough to accept Arabs into their own country and grant them full citizenship when Palestinian Arabs wanted all of them killed. Only the Jews have the moral and legal rights to Israel. And historical revisionism (anti-Semites are the ones doing this) can't change this fact.
I do not know where you are getting your historical data, but for starters, the modern state of Israel came to be on the year 1948, not by the "19th century." More importantly, Israel
is not a "barren wasteland" as you claim. It does host a desert, yes, the Negev, but most of the area is fertile, not barren. Long before Israel popularized its use of drip technology to access the barren areas, it was making a living in the abundant soils elsewhere in the country. Thus, your statement that "The truth is that the majority of Arabs in Israel have immigrated to it only during the 20th centuries due to the economic boom in pursue of a better life" does not hold water, but I would not blame you for following the popular anecdotes of the time. It is just too tempting to believe in the all-conquering Jews script.
Blood enmity and historical shortcomings are largely to blame for the breakdown of Mideast territorial arrangements as far as the Jews and Arabs are concerned. So many issues are at play that there is no way we'd be seeing a solution soon, especially in our lifetime. For example, even doing without the ancient records, it would still be a hard pill to swallow for Arabs to just wake up with their hated brothers (literally) the Jews in their midst suddenly, after living without them for so long. The Jews answer with cunning and technicalities. The old and new powers meanwhile just want to get rid of the perceived guilt and dispose of the ancient Jewish problem once and for all. It is a continuing story, so not very wise to cast the vote on where all of these is going. Suffice to say, with all the money that the Jews have come to acquire through the centuries, why didn't they just finance Columbus's voyage and claimed even just a piece of the New World as the new Promised Land
Again, the root of the conflict is not that any villainous Arab in league with the Devil Hitler just wanted to throw away the Jews out of the Middle East. It is just so naive and superficial a take on the matter. It goes way deeper, of historical bad blood between the two relatives, of lands and birthrights swindled and forfeited, of Jesus and Mohammed ascendancy, etc., etc. The funny thing is that we find ourselves enmeshed in their conflict just because of the fairy tale tie.
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But religion is not meant to explain the natural world, although ancient religions used to do that, i.e. paganism, until monotheism corrected man's misperception of nature and the Divine. The Bible is a spiritual book and as early as the 4th century long before modern science was conceived, St. Augustine of Hippo, warned against the literal interpretation of it. The Genesis account was never viewed as a literal truth by Christians at that time until the 20th century with rise of Christian fundamentalism. In fact, the 14th century Jewish rabbi, Nachmanides, had to interpret the creation account of the Hebrew Bible of which he came up with a similar interpretation as that of the Big Bang.
Science explores our physical reality. But it doesn't say how many possible realities are there are or if the physical reality is the only one that exists. Religion explores transcendental reality. And it is based on revelation of which you are free to NOT believe. Religion has little to do with science for the reason that they are intended for different purposes so there is no point in comparing or pitting them against each other. Religion only concerns about the spiritual relationship of people to God and to one another, and to give meaning to scientific pursuit. Science doesn't try to explain meaning or purpose or spiritual connections nor religion tries to explain the natural world. They are not meant to substitute each other. When properly viewed, science and religion go hand-in-hand and in fact support each other, each addressing part of the whole picture.
"But religion is not meant to explain the natural world...." Tsk, tsk, tsk. My, I wonder how the pope, the whole of Vatican, add to that the Orthodoxy would react to this statement.
For the longest time until Galileo and other lights of science told them otherwise—even at the cost of life—the whole of Christianity monopolized all of astronomy, medicine, education, and virtually all piece of purported knowledge
to explain the natural world, where nothing passes for academic and public consumption, by publication or any form of dissemination, until the church says so, until it is decreed that not one content offends and goes against
official world view. Against this suffocating backdrop, the likes of Darwin, Bruno (the philosopher whose insatiable search for the truth was finally—mercifully—ended by church authorities by being burned at the stake) paid with verbal or written castigation, physical threats, career termination, and excommunication or death. And why not? God says so.... After all, he is omniscient and omnipotent, so why not his chosen men?
By apologizing for its past atrocities, even if late in coming, at least the Vatican has learned its lessons fast or be faced with obsolescence quickly. So it has adapted to the times, though leaving many issues still hanging and unaddressed, at least until it is still safe to do so. The Romans always win and so it has stood. The physical empire is gone, but they have the spiritual fortress this time, along with the unceasing contributions—tributes, really, but now euphemistically called tithes—and other benefits of course. Pity Gomburza who thought the issue in question was all a matter of pure faith.
