In my limited understanding of the wealth of scientific knowledge in the world around us, I know that scientists pose questions or hypotheses, and go about gathering evidence to provide facts. These facts, then, denote the truth.
In collecting information or evidence that supports a specific question, the ability to present this evidence gives a specific answer. It may not be a complete answer: it may present an additional question that must be answered in order to get the complete truth.
How then to show that evidence is truth? This usually takes place when one can see with his or her own eyes the truth of a situation. So that when I speak of something with evidence to support it, there can be no argument that I am not telling the truth.
For example, in understanding that when temperature increases boiling appears, water is placed on a flame, it is watched, temperatures are regulated, observed and measured, and the facts or evidence shows that water boils. If someone wants to prove that salt makes water boil faster, then salt is added to the water. Heat is provided, temperature is measured, and records are made available to compare the time it takes for plain water to boil as opposed to plain water.
It is through experimentation that we gain knowledge and evidence.
Evidence can only be deemed valid if it can be proven to be true. In the scientific world, the facts are gathered using the scientific method, where an investigation to find answers...
Evidence is not subjective in nature. In other words, it is not based on a person's opinion. The question may come from a person's opinion, but it cannot be considered evidence until a theory or hypothesis is tested, data are collected, and evidence is proven to be correct.
What links evidence to belief are facts that are collected. There is a differentiation, then, between believing by facts or believing by faith. For in believing by faith, facts are not available (or needed). This then provides a distinction between what is evidence and what is opinion. Opinion has no place in the world of empirical evidence.
So belief is...
While evidence may be a pathway to belief, belief does not require evidence. The only evidence that one can strictly call truth is that based on information supported with scientific study and the production of supporting facts. (Or by observation, in general.) Belief can also take place based upon one's opinion or faith. This does not come with evidence, but this kind of belief can still be very strong.