Thank you for your question. The subject of neuroscience and spirituality is a big topic today. I would be very interested to see the questions that come in to you on this subject, as i am currently writing a book on this very subject. One of the chapters addresses the question, ‘Is religious experience just brain activity?’ which i think is what your question focuses in on. Someone who has looked into this and written a lot is Andrew Newberg. His book ‘Born to Believe’ would be a great place to start. The following books also have chapters on religious experience.
The Spiritual Brain by Mario Beauregard & Denyse O leary,
All in the Mind? by Peter Clarke, and
Minds, Brains, Souls and Gods by Malcolm Jeeves.
There is lots that can be said, but a good starting point is that it should come as no surprise that there is brain activity in parallel with a religious experience. God has made us as spiritual and also physical beings and the the work together. in some ways, i would be more concerned if there was no brain activity during a religious experience! Yet, the observance of brain regions doesn’t in any way remove God from the picture. We know some of the brain regions that ‘light up’ when someone is experiencing romantic love but this doesn’t cause us to say that the relationship was therefore not real. Understanding the underlying mechanisms is only one level of explanation. In fact, the reality of the relationship is why there are brain areas lighting up in the first place.
There is lots more that can be said. But we also know that there is far more to being a Christian than an isolated ‘experience’. It is about the historical reality that Jesus is risen and He offers us life in the ordinary things of life as well as the extraordinary mountain-top experiences.
This perhaps is a starting point. I hope it is helpful,