' Happiness or unhappiness '...

Our thoughts have prepared for us the happiness or unhappiness we experience.

Bowl of Saki, by Hazrat Inayat Khan
Commentary by Pir-o-Murshid Inayat Khan:

All our possessions, all that we collect in life, all these things which we shall have to leave one day are transitory; but that which we have created in our thought, in our mind, that lives. A person thinks, 'Some day I should like to build a factory.' At this time he has no money, no knowledge, no capability; but a thought came, 'Some day I should like to build a factory.' Then he thinks of something else. Perhaps years pass, but that thought has been working constantly through a thousand minds, and a thousand sources prepare for him that which he once desired. If we could look back to all we have thought of at different times, we would find that the line of fate or destiny, Kismet as it is called in the East, is formed by our thought. Thoughts have prepared for us that happiness or unhappiness which we experience. The whole of mysticism is founded on this.

Every good or bad word or deed is reproduced before us, though it seems as in a dream. If we watched life keenly, we should see how true this is. Joy, sorrow, love, all depend on our thought, on the activity of our mind. If we are depressed, if we are in despair, it is still the work of our mind; our mind has prepared that for us. If we are joyful and happy, and all things are pleasant, that also has been prepared for us by our mind. It is only when our mind works without control that unhappiness, sorrow, trouble, pain, or whatever we experience comes without our intention. No one could wish to create hell for himself; all would create heaven for themselves if they could; and yet how many allow their minds to create these things for them, regardless of their own intention.

The control of the activity of mind is called concentration in the language of the mystics. The meaning of this word is often not rightly understood. People are apt to think that concentration means only closing the eyes. But one may close one's eyes for hours, and still the thoughts keep coming like a moving picture. People are never at rest, never at peace; anxiety and sorrow do not disappear just because they close their eyes. It is concentration that does that. Concentration is activity of mind in the direction desired; our desire dictates in which way the mind is to be active; the mind acts according to our wishes.

In point of fact, whatever one makes of oneself, one becomes that. The source of happiness or unhappiness is all in man, himself. When he is unaware of this, he is not able to arrange his life. As he becomes more acquainted with this secret, he gains mastery. The process by which this mastery is attained is the only fulfillment of the purpose of this life.