What is truth? Truth can be defined in many ways such as: honesty, reality, loyalty, devotion, certainty and many others. As an individual I have not always been truthful about everything and I know most people have told a lie at least once in their life, even if it is just a little fib. But I have learned that in order to keep things good the truth must always be told. Lots of things can be based on truth.
Looking at the issue of truth verses falsity. The statements in an argument can be either true or false. But how do we determine whether they are true of false? That question is the concern of logic. Logicians are concerned only with the form of an argument and not about its content. And the reason logicians can ignore the truth of falsity question is that an argument can be valid even thought one or more of its premises is false. Looking at the other end of that statement, an argument can be invalid even thought all its statements are true. It is not silly to argue about things that are false, since this is the best way to work out the consequences of untried possibilities. Our text book gives us examples of what would happen if we were to jump from the fifth story window of a building? We would get hurt. Although we haven't really jumped and we have not gotten hurt this is because our reasoning was correct that we would get hurt if we were to jump.
Discovering the distinction between truth and validity was a huge step forward in the study of human thought. As far as we know, Aristotle was the first thinker to make the distinction explicit, and it may well have been his most important contribution to the development of logic. Although it is surprising how many people centuries after Aristotle's time still have trouble with this distinction.
Of course what we want are arguments that are valid and whose premises are true. Logicians refer to these arguments as sound. Unsound arguments may be either invalid or valid arguments that contain false premises.