In my experience, and I am experienced, set and setting are still most pivotal. Your mindset regarding the experience itself is hugely important. It's not the placebo effect because there's obviously neurochemical interactions between the chemicals and yourself, but your own perceptions about whether or not the experience will have meaning do impact the long-term results in my opinion. I say this having seen other people's experiences with psychedelics and my own and being somewhat let down at the less mystical nature of the substances and more the fact that they did impact me but not necessarily in the ways that have been hyped up socially. There's absolutely impacts from taking psychedelics on your experience with the world around you, but whether or not it's a religious like experience, I think has to do more with the user. That being said, dimethyltryptamine is quite the ride