it depends on what you mean by “true”.
And it is also depends on how you define ”proof”.
For instance, in everyday usage and in matter of legal terminology, proof and evidence are synonymous, but not so in (natural or physical) science and in mathematics.
In mathematics and in science, the word “proof” is defined as logical statement or logical model, often expressed in math equations or formulas, which often contain combinations of numbers, variables & constants...hence equations or formulas are definitions of mathematical proofs.
Mathematics, such as equations, are useful tools that help with understanding physical & natural phenomena, as parts of the explanation.
To give you some examples Ohm’s Law is a brief statement about the relationship between electric current, voltage & resistance (resistance of conductor), that can be expressed mathematically in an equation:
V = I R
This equation is proof, not evidence. The equation is abstract & logical model or representation of electricity in a circuitry, hence the equation is proof.
But the science required that all explanations, all predictions, plus all equations must be TESTED, to verify if these equations, predictions & explanations are scientifically true or not. And the only way to test them, are through observations of evidence or through experiments.
No explanations, no predictions and no equations (or no proofs) are true “by default”, until you have evidence or test results of experiments that can verify & validate them. So if built a real circuit board, wiring with some resistors (conductors) together, and apply electricity to the circuitry, you can test the current, voltage & resistance of the resistors, using device called a multimeter.
The readings, the values, from the multimeter are your data. Data are essential components to your observations and to your tests. So the data themselves are also your “evidence“.
Your evidence is the circuitry (board, resistors, wires, and an electric source (eg battery), plus all readings you obtained from the multimeter - those are all your evidence. To check if the equation to Ohm’s Law is correct, you can input the values, eg current and resistance to one of the resistors, and see if the solution V (voltage) match with the voltage from the multimeter. If it match, then the equation is true and it works.
That’s how you verify and validate if the Ohm’s Law is scientifically correct, by testing the equation.
of course, experiments can go wrong, but this can be determined if one of the components are faulty, for examples, the wiring is broken, or the resistor have shorted, or the multimeter is damaged, or perhaps electric source is faulty (eg flat battery). So you would replace the wire, or the resistor or use another multimeter or use another battery. If you have some basic knowledge of circuitry, you should be able diagnose where the fault lies, and fix it, by replacing the multimeter, battery, wire or resistor.
So what would happen if all the evidence and experiments don’t support the explanations or predictions or the equations? That would means your hypothesis is wrong, including whatever equations you have, and that means the proofs are also wrong. And if the equations & explanations are wrong, then your hypothesis have been refuted by the tests.
It is the tests (eg evidence, experiments & data) that determine if the hypothesis is true or false, probable or improbable, verified or refuted.
if the equation or mathematical proof failed the test, then the proof is wrong. The evidence isn’t wrong.
So when you talk of “proof” in science discussions, then you should know that proof is defined as an equation or a formula…so proof is only possible solution that can be wrong, especially if the tests or evidence doesn’t support the equation or proof.
From my experiences, here and other fourms, creationists seemed to confuse proofs with evidence. They are not synonymous in natural sciences or physical sciences.
Getting back to your question, belief is like personal view or personal opinion, belief is highly subjective. It can be true or it can be false.
it is subjective because belief are accepted as being “true” by one’s own conviction. Another word for conviction, is faith. Faith is about trusting your belief, even if the evidence don’t support the belief. That’s the problem with faith-based belief, it relies on one’s own acceptance of what is true…I would call faith by another name - “bias”…or in terms of logic, faith-based belief is essentially “confirmation bias”.
What I find really strange, is that creationists actually commit all types of logical fallacies, eg circular reasoning, argument from ignorance, argument from incredulity, false equivalence (eg using irrelevant analogies, like the infamous Watchmaker analogy with Intelligent Design, when arguing against Evolution), false dilemma, attacking the strawman, moving the goalposts, etc.
Anyway, belief can be true or false, but that’s really depending on the situation, and whether or not such belief can be verified.
For instance, I can believe that my parents love me, I don’t need evidence to support this belief. My belief is true to me.
But if you are talking about belief in something “supernatural”, like belief in god, angel, demon, jinn, spirit, ghost, fairy, afterlife, miracles (eg Jesus turning water into wine), magic, etc…none of these can be tested, and in science, these things are ignored because they cannot be tested. So, I would say no…to anything that are “supernatural“.
Your question is too general and vague, to give you a proper answer.
as I said, it really depends on the situation. Can you be more specific as to what “belief“, you are talking about?