I have heard and read some religious apologists argue something to the effect that we have no more reason to believe our ordinary experiences than we have to believe our religious intuitions and experiences.I am curious to know how far is such a stance philosophically and scientifically defencible.Thanks in advance
Personally, I'm in sympathy with this concept. However Hume has an entire discussion of this topic --his answer is essentially that mundane experiences match a reliable pattern, while religious experiences are outliers.
As someone who has had religious experiences myself, they definitely serve me personally as supporting evidence for my religious beliefs. However, I understand why Hume would claim that my report of my experiences are unlikely to serve as compelling evidence for anyone else.
In the East the problem is come at from an entirely different angle. The subject is dealt in detail in the Mandukya Upanishad and Gaudapada's Karika (a commentary on the Mandukya Upanishad). What you call 'ordinary experiences' are analyzed as experiences of the waking state. The Mandukya analyzes the experience of the universe from the different states of consciousness; waking, dream, dreamless sleep, and Turiya (Super-Consciousness, Nirvana, Samadhi - 'religious experience').