Are spiritual experiences real?

There is no absolute answer for this, since the brain is not well understood yet. However, there is a huge possibility that our brain is playing tricks. Such experiences is very personal since others might not experiences it under the same situation. Therefore, like what some scientist had said, it is self-deluding. It is personal experience, you are not supposed to draw a conclusion based on personal experience. If we treat personal experience as facts, it will be the same as treating what a lunatic had said as literal truth as simple as that.

Spiritual experiences is not caused by malfunction of the brain, it is already hard wired in the brain that we can experience such questionable thing. Drugs affect the brain by chemically stimulating parts of the brain that is linked with imagination, generating what most of us call hallucination. On the other hand, magnetic field influences the brain since the brain works by using magnetic  pulse, albeit a very weak one. How magnetic field affect the brain is still nothing much understood yet. However, once we understand much more about how the brain works, the scenario like The Brain in The Vat is likely to happen. We might be able to distort what is perceived as reality in the eye of the object.

As ethologist, Richard Dawkins had dedicated an entire chapter of "God Delusion" on the evolutionary root of religion. He argues that religion could sprung up because those who heed the words of authoritative figures have higher chance to survive in Darwinian World as they religiously follow what they are not supposed to do what could endanger their life. A child that do not heed what their parents or other grown ups is less likely to survive as he might plunge himself into life-threatening dangers. With such submission to an authoritative figure hardwired into our brain, it is easy for those in the authority to create a beliefs system as such figures usually also play the role of a sage.

Beliefs is something slowly being hardwired in our brain as generations roll. It is an evolutionary product to keep our tribal ancestors united.