I want to provide two forewarnings: first, it is...
Universal Truth/Morality
I want to provide two forewarnings: first, it is necessary to be very specific and careful about what language means on this topic. I will lean heavily on the distinction between what we can know and what we do know. If my language is confusing, ask about it in the comments and I'll get back to you. Second, I am not religious, so I won't be using that as an argument. Your thesis is plainly stated: "I believe that truth is not universal, but relative and that it changes as a result of personal opinion" I have a few arguments: 1. Does this argument apply to the claim that truth is relative? That is, is the claim that truth is relative also relative. If so, when I disagree and say that truth is not relative, what could your response be? You can't disagree with me, because truth is relative. How can I take anything you say seriously and how can you have a debate at all? 2. I will define truth roughly as "agreement with reality". So, proposition P is true IFF (if and only if) P is the case in the world. Now, a basic principle of logic is the law of non-contradiction which states that two mutually exclusive claims cannot be simultaneously true at the same time. So, let's take the claim that I am typing and the claim that I am not typing. Both cannot be true and both cannot be false, because they contradict, so one must be true and one must be false. This fact is true for all people, in all places, at all times. Now, this does not mean that I, or anyone, knows which is true and which isn't. I am highly sensitive to the claim that it is beyond our epistemological ability to know what the truth is in many situations. But, what I am arguing is that TRUTH itself is not relative, the problem only comes in our ability to approach truth.