Having come from, and abandoned, a very Jewish and very observant background, I have come up against much impassioned pleading for my soul. And out of the mouth of every single teacher or lecturer who has tried to help me, barring those of the "Discovery Seminar" school (which manipulates Hebrew letters and Bible codes for cheap impressive thrills) has come the following strident argument, which, unfortunately, I am at a loss to convincingly refute:
Judaism is the only religion which pins its authority to an event which a large number of people witnessed. Specifically, according to the Bible, God spoke to the Jews at Mount Sinai. According to the Biblical count there were 600,000 men there between the ages of 20 and 60, along with a corresponding number of women and children. In times to come, how could a transcendent event like that be falsified? There is no way that an entire nation could be convinced that it had witnessed something that it hadn't!
I have heard this so often, I have it memorized. And though there are alternate explanations for what really happened at Mount Sinai, including extreme thunderstorms and/or hallucinogens, the Sinai claim does separate Judaism from other religions that come to mind, which are often based on a divine revelation to one person. Can anybody come up with an exception?

bookw56 says Actually, Christianity has the same claim. The events of Jesus' life are well-planted in history, with all the dates, places and names checking out both archaelogically and through the historical records of Josephus and the records of the Talmud itself. Plus, the Gospels mention the large crowds who gathered to see Jesus preach. In Paul's Epistles, he gives specific names of disciples and witnesses of the events surrounding Jesus's ministry, death and resurrection. Plus, the New Testament is one of the most accurately preserved works of the ancient world