What evidence is required to establish a fact?

An Argument can be just a statement, a reason or set of reasons or even a fact depending upon what relevant evidence is provided in support of the arhument. Many people tend to confuse the terms and call their argument a fact, intentionally or unintentionaly, basing their argument only on circumstantial evidences, however vague that may be. For example, I have a habit of studying me subjects. I use to study a poster at Mylot to answer his/her question, in perspective, which i can't just guess by the topic presented. What i have concluded about you is that you are an ardent fundamentalist (not to be taken in negative connotation but by original definition)Creationist American Christian who love to talk about basics of a phenomena and philosophy and who is keen to know about india with a positive attitude etc etc. Now my assertions are based on some evidences. The evidenc is my survey of your whole profile, the discussions you started or replied to, comments made by you etc. Now my assertions may or may not be a fact. This assertion that my assertions may not constitute a fact about your personality is still based on some evidence based on experience about people that there are people who are different from what they appear generally, the evidence that i don't know how you are in personal, social and spiritual life. These conditions of ignorance in other aspects about you, sheds a doubt about my first assertion, about your personality, so i can't say that whatever i said about you is true or a fact because all my argument was based on observation of your profile, which may or may not be true or even if true does not take into account your whole life and experiences. Having said that, sometimes the definitions of hard and solid evidences are subjective which further are based on subjective circumstantial evidences. For example, for a creationist there are many solid and hard evidences about a creator, based on circumstantial evidences, which atheists disclaim to be true or solid evidences. Similarly evolution propagandists declare theory of evolution as fact while producing evidences which are considered as just circumstantial and not solid evidences by creationists. So in this regard, a compelling evidence itself becomes subjective. For an argument to constitute a fact, in my view, the evidence should be relevant and relevant evidence must be objective, un biased and based on already established facts and empirical data. It should be observable, certifiable and empirically provable. I would not go into details about the subjectivity of definitions of the terms that i have used above. Just to touch the issue though, in my view, existance of GOD is observable and certifiable, though not by our senses but by thinking and sound logic, but the same is not acceptable for many atheists. In my view science is too little to encompass the whole wisdom but for others it either got factual answers ot has full capability for the same. So the definitons cross at some point based on the basis of the sytem one is arguing with.