When citing the evidence they have for the existence of a god, many religious people will give examples of their own personal experience. On every such occasion, these references are discarded.
The reason is simple. In science, all measurable effects are measured several times, often in several different ways by different scientists. The methods are then examined by other scientists, as are the conclusions, to try to remove any and all bias that may be present. This ensures that the results obtained are objective.
Personal experience cannot be reproduced by a sceptic, therefore it cannot be verified by someone who is unbiased. This is why it does not count as evidence.
Even if a sceptic could reproduce the same effect in their brain, the method and conclusions would still be swept aside. The only conclusion that one could come to is that, under certain conditions, the brain can believe various religious statements to be true, not that they objectively are true.
So it doesn’t matter how much you believe something to be true or real, that does not make it objectively true.