Spiritual knowledge is a regular science. Just as two and two make four, similarly everything is clean and obvious here also and there is no scope for any kind of modification or change in that.
Spirituality is the science of the soul, and the soul is a conscious entity in the body. The way back to God as offered by the Masters is one of developing inner consciousness with the aid of holy Naam (the Word).
All suchlike outer aids (as drugs) resulting in temporary hallucinations, are certainly a mockery for the divine grace. You can well understand the vast difference between having a conscious and wide-awake approach for proceeding within and that which makes recourse to these outer aids which are no less than opiates creating sensual vibrations.
You will recall that the observance of a strict diet by avoiding all flesh food, intoxicants and opiates, is a basic essential for inner spiritual progress, for attaining a refined state of mind. We have to develop consciousness, the divine attribute of soul, and for the achievement of (inner) consciousness, inner and outer piety and chastity are very much needed.
The drugs are equally harmful, and should be avoided, which dull the brain and cloud the mind with vague feelings of distrust and confusion.
Sant Kirpal Singh
Question: Master, most of us here, before we came on the Path, have taken drugs. Will the fact that we have taken drugs adversely affect our spiritual progress?
Sant Kirpal Singh: Surely. I tell you, we are conscious beings. We have to become more Conscious. Anything which has gone to mar our consciousness – that will take you to the lower strata of life. That is killing yourself, I would say.
Question: A lot of us became aware of the spiritual life through drugs ...
Sant Kirpal Singh: Leave it, that's all. Don't take more poison, that's all. A little poison taken can be ...
Question: But our progress now will be affected by what we did before ...
Sant Kirpal Singh: Only if you put in more time (in spiritual practices) these things will be cleared. Put in more time. Don't leave off that effort. That's all right. Whatever poison you have taken in your stomach can be washed out. But stop taking more poison, that's all. What more is there?
(From the book "Light of Kirpal", chapter 31)
Question: Do those who take drugs such as LSD and have certain experiences—are they valid experiences?
Sant Kirpal Singh: No, no, they are hallucinations. That’s the death of the soul, you follow me? The consciousness is lessened, naturally they will have to go to the lower planes. That is all this intoxication starts, it is still more death to the soul. It is deterioration. Definitely going down to beastlihood. Even a snake is conscious but there are different degrees. Man’s consciousness is more. If you use suchlike things your consciousness is affected. You will have to go to the lower planes. I appreciate your kind sentiments for your friends when you wish them to progress spiritually. The so-called spiritual experiences, had under the spell of drugs, are misleading and are rather likely to affect your inner progress. Spirituality is a research into the realms of reality — the consciousness. Drugs, opiates and intoxicants should not be partaken as these will not only affect your health adversely but shall be detrimental for your spiritual progress.