What truth is really the truth?

During a branch of a conversation today in class, the topic of truth was brought up. Where does truth come from? How do we know when and what to believe? We also discussed where people get their sense of what is right and wrong. We concluded that for many people they simply look to the bible and follow God's word. These sorts of people can be difficult to have a conversation with. The parents of someone I know very well have this firm belief that what is in the bible is what's right, what ever God says is how you should live your life. This has been such a life struggle for my friend and his siblings to deal with. Any thing that goes against their parents religious beliefs is not tolerated: certain hobbies, friends, and music preferences. All of these decisions are based upon God's word. The most frustrating part, which was mentioned in class, is when their children ask them to explain their extreme judgment and sheltering they reply with various statement that all boil down to basically mean "that's just the way it is." I give them credit for putting up with this, they are not accepted for who they are and they are forced to feel as though they would let their parents down if they knew who their truly were. All of this could be avoided and a much more understanding parent-child relationship could be formed if they just branched away from seeing the Bible as a rule book. Every individual has a chance to decide what is right and what is wrong on their own. I think that is what should be taken away from the Bible. It lays down rules, but those rules like humanity and the world itself must evolve and change. People are so different for a reason, we all mess up in our lives we all do what is wrong, but we learn from it.  We grow from these mistakes and they shape us into unique human beings. 


Question: Do you think that when parents say "because I said so" it is just a cop out of explaining themselves? Or do they actually have a set of rules that they stand behind and could explain if they wanted to?