Not all that seems spiritual comes from God. Ecstasies, visions, higher states of consciousness, mystical intoxications, all these and more can come from that level of the inner world which reflects higher, truer levels in a parodied or distorted form rather like the reflection of the sun on water. The 20th century saw this sort of thing like never before, and much that is called spiritual now actually emanates from these worlds. Such states do not lead to God but to illusion, pride and, if pursued, spiritual corruption, ending up in a greater separation from God than that of the everyday materialist.
How does one tell the difference between true and false? It comes down to what is in the heart. Those with pure motive and clean heart who tread the path out of love for God are unlikely to be deceived and, if they are, will learn from the deception relatively quickly and move on. Those who seek experience may get experience. They won't get truth. Those who seek truth may sometimes fall into error but they will be safeguarded by their fundamentally honest motivation. The impure self will attract impurity to itself. The self striving for purity for the sake of purity and not for the sake of what it may gain thereby will be open to levels of light undistorted by the action of the worldly ego which bends all it receives to reflect its own state.
True illumination is not simply an experience of joy or ecstasy. It is above all a moral experience which may elevate the soul but also reveals to it its utter dependence on God. There is no inflation or, if there is, it is not one of the individual experiencer but of his receptivity to God, and this will actually diminish the experiencer in his own eyes. True mystical experience makes humble. False experience puffs up and deceives.
I say false experience but actually the situation is not quite that simple. For the false is not completely false. It is a false representation of truth, like a counterfeit note or a mirage, and, to add to the potential for confusion, while it is not true, it does have a borrowed reality which makes it not completely a lie. In addition, compared to our normal mode of consciousness, it may seem much deeper, more alive and more intense. But then so can drunkenness compared to sobriety.
Everyone who is moving from a spiritual attitude exclusively deriving from following external authority to an inner spirituality that seeks to know for itself what it has only hitherto been told, and to know it as a fact of consciousness, needs to be aware of the dangers of spiritual deception. We are often told nowadays that there were esoteric groups in the past, whether followers of mystical teachings in the East or hidden occult orders in the West, who had a greater understanding of real spirituality than existed in the mainstream. Sometimes this is true. Often it is not. Those who have broken through to the inner worlds by whatever means, whether spiritual practices or yogic techniques or whatever it might be, even drugs, are by no means guaranteed a true vision. If they themselves are not true, they will not get truth though they may get an approximation of it that seems true to them. But unless they learn to see through the distorting waters of what is sometimes called the astral plane, that zone above the material in which spiritual truths are converted into mental images, they will remain in illusion. And the only way they can learn to traverse these waters safely is through purity of heart and love of God.
This is the difference between the true and the false. It is a matter of motive. Do not think that lust applies only to the flesh. There is a spiritual lust too and those guilty of it may gain some kind of experience they call spiritual but they will never know the true mystical marriage between God and the soul.