A negative can never be proven. Prove pigs fly. Prove I can't fly. Prove martians don't exist. Prove eagles don't spit magma. These statements, nor any statement for that matter can ever be proven 100 percent with regard to philosophy. However, compounding evidence and stacking the odds for a specific question enables validity.
For instance, does the Herpes Zoster Virus cause chicken pox? The answer: most likely. One can never be certain.
Whether truth is relative or absolute is a matter of subjective opinions. I understand many truths are absolute, while others are relative. Given my educational level, you and I would disagree on matters as absolute or relative; however, remember,
I have compounding, reproducible, stand-alone-evidence that gives validity to what I "believe". Moreover, tangible results that enable benefit or harm could be demonstrated at numerous levels on a plethora of topics, substantiating the aforesaid statement.
The answer: truth is both or only one option depending on the individual. However, those that give advancement to society see many truths as absolute, and not relative (scientists). For instance, vaccinations, cancer treatment, surgical procedures that enable life-sustaining/saving methodologies to be repetitively implemented with success, etc., are considered absolute truths by those who perform the task to safe a life and by those saved.
If you can't get past the philosophy of the relativity of certain matters, then you will under-live your true potential and for this, I pitty you and wish you a great education that enables a revelation.
As for the Big Bang theory, refer to the red text. Christianity is none of this and therefore, is not a valid belief. If you still disagree, I demand a full paper from you within 2 weeks explaining the big-bang (in paraphrase of course, of how it occurred and why scientists state they've detected remnants and how these remnants correlate to the Big Bang itself). Keep in mind, the writing of this paper must include references from reputable academic sources (peer-reviewed, which are validated through an objective means). Only then will you truly come to appreciate the red text listed previously. If you don't understand something written, then consult another source for clarity. Off you go.
http://godisimaginary.com/