When I was a college student, one professor often frustrated us. When we would ask him a question, he always would answer, "I just don't know. But if you can wait until our next class, I will try to have an answer for you." And he always did. At first, we wondered about this professor's intelligence. Eventually, we recognized his wisdom. Rather than quickly give an answer which might be wrong, he took the time to search for correct information for his students. Sometimes the best answer is, "I don't know." An old saying suggested that it was better to be silent and be thought a fool than to open one's mouth and remove all doubt.
Some questions may not require an answer. A college classmate, when asked whether a rumor about his holding a controversial position is true, sometimes answers, "How about that?!" Religious discussion focuses at times on intricate issues. To be frank, we may not need to know all the answers on all the issues. If something is going to happen after my death whether I believe it or not, then I should just trust God to do his job well and not argue if he does it differently than I thought he would. After all, it's his universe. Other issues are more immediate; I need answers yesterday! How to be just, how to show mercy, how to know the difference between right and wrong in today's streets - these demand answers, for they determine the direction of people's lives. Harmful decisions may alter history.
It's alright to admit ignorance; it usually is wise. So, if you don't know, ask. Search for truth. Apologize when you're wrong. And keep searching.