Please works better. You're firmly and utterly convinced that your viewpoint is correct, so to you, that's a valid truth, yet I see things differently and disagree with you. But does that mean that my view of the situation is any less valid than yours is. So truth is subjective upon the current viewpoints, and as EFL said, we can disagree on things, but our views are still valid.
We used to hang, draw and quarter people, now we don't; so 200 years ago, public executions were an acceptable practice, and no one thought anything of it. Now it's considered an abhorrent, so truth is fluid. Now you and I both agree that greed is wrong, and I suspect you'd agree with me that most politicians are useless at best, and corrupt at worst, but you'll still support a Labour point of view, whereas I support more of right wing one.