How to know which side tells the truth?

In a recent Fireside Chat -- my weekly podcast for PragerU, half of which is dedicated to my taking questions from (mostly) young people around the world -- a man in his 20s asked how he was supposed to figure out who is telling the truth and who isn’t. He undoubtedly was speaking for millions of his peers. Given the opposing positions one encounters on almost every issue, how is one supposed to…