Freedom of speech and questioning

Whenever I ask a question: how can you prove the existence of soul? I get countered: how can you disprove it? I stopped the discussion then because asking a counter question is not answer to a question. I see lot of such counter questions in day-to-day life. Why people feel hard to say these simple words: "I don't know". Instead they defend it as if they own it. We are not founders of Hinduism, and there is no point in defending it. Just because we are born to Hindu family, we don't have right to defend it, instead we should dare to question your parents, why they believe what they believe. Some parents agree that their parent's told them to do so. Some try to defend it and scold you for questioning them. The freedom of speech stops from the home, why bother govt stopping you. The basis of science is questioning, which we already proved to the world we lack it: just see our scientific progress.