I can't help with the smart people believing in the Gospels question, I don't get it either, but I'd imagine they'd describe it as a leap of faith. That's not to say there aren't holes in their history, as you pointed out to your prof. There are a lot of historians that focus on various subjects from single dimensions, ie. a US Civil War historian that focuses on the military history (specific battles, troop movements, military strategy, etc.), but not so much on the social history. They can have holes in their conclusions if the focus is too much in the details. It sounds like you're taking an intro to western civilization class, which is a very broad topic. When I took this class, my prof's area of expertise was the Spanish Empire, she didn't know a lot of details beyond her area of study. It's an intro course that is generally taught by the lowest profs on the academic totem pole.
History isn't an absolute, it's open to interpretation, and some historical sources are problematic (the Gospels are totally problematic), and even the best primary sources have their issues. I was a history major, and before graduation I had to take a class on problems with historical sources (frankly, I thought it was one of the best classes ever and should be taught on the 100 level of college courses). It showcased how, as a historian, one always has to keep in mind the author's bias and historical context. Some people who study history aren't very good historians and are subject to their own biases, prejudices, and their own historical time period. History is really a balancing act, one always has to remember that "history" is written by the victors. If one wants to have a full view of whatever time period being studied, a balance between micro and macro history is necessary (for instance if studying the influence of the East on the West in the time period of Marco Polo, it's necessary to have a basic grasp of both Eastern and Western cultures and history of the time period, plus to keep in mind the Euro-centric view of most Westerners from that time). This is further complicated if one looks at minority history. Example: What was life like for peasants in the middle ages? Very complicated as all sources from the time period were not written by peasants, therefore there aren't any direct primary sources on the subject. Doesn't mean that all sources are null on the subject, but need to be viewed through the correct lens. I love history, I love the messiness of it. I rambled on, but I hope you don't write off the subject, write off the prof.
History isn't an absolute, it's open to interpretation, and some historical sources are problematic (the Gospels are totally problematic), and even the best primary sources have their issues. I was a history major, and before graduation I had to take a class on problems with historical sources (frankly, I thought it was one of the best classes ever and should be taught on the 100 level of college courses). It showcased how, as a historian, one always has to keep in mind the author's bias and historical context. Some people who study history aren't very good historians and are subject to their own biases, prejudices, and their own historical time period. History is really a balancing act, one always has to remember that "history" is written by the victors. If one wants to have a full view of whatever time period being studied, a balance between micro and macro history is necessary (for instance if studying the influence of the East on the West in the time period of Marco Polo, it's necessary to have a basic grasp of both Eastern and Western cultures and history of the time period, plus to keep in mind the Euro-centric view of most Westerners from that time). This is further complicated if one looks at minority history. Example: What was life like for peasants in the middle ages? Very complicated as all sources from the time period were not written by peasants, therefore there aren't any direct primary sources on the subject. Doesn't mean that all sources are null on the subject, but need to be viewed through the correct lens. I love history, I love the messiness of it. I rambled on, but I hope you don't write off the subject, write off the prof.