Heroin, cocaine, and alcohol can indeed open up the mind to altered states of consciousness, as can music, poetry, and meditation. However, do not think these experiences give you new insights into reality, or that they are even remotely spiritual. Drugs like these can serve only to help the ego forget its problems, and only for a short time. They dangerously suppress the symptoms, but do not cure the disease. You may well experience a rare heavenly bliss and warm sense of fulfillment, though I bid you think again! Soft drugs invariably lead to hard-drugs. Small superstitions give birth to gross miscarriages of reason.
Far from bringing us closer to reality, such practices distance us from it by making us content with a dream. At least at other times reality is close enough to foil our plans.
This is not to say altered states of consciousness are without their use. With intelligence, they can help to make us aware of the many faces of reality, and thus that reality exists purely within the mind. Unfortunately, the herd look no further than their present comfort, and cannot learn from experience. Implications and consequences are alien concepts to such animals, who are fully occupied just keeping from drowning in the stormy seas of their lives. They have no time for investigating the nature of life and death: they have no time to live.