Joy and Sorrow...

Joy and sorrow both are for each other. If it were not for joy,
sorrow could not be; and if it were not for sorrow, joy could not be
experienced.

Bowl of Saki, by Hazrat Inayat Khan

Commentary by Pir-o-Murshid Inayat Khan:

Life is differentiated by the pairs of opposites.

If there was no pain one would not enjoy the experience of joy. It is
pain which helps one to experience joy. Everything is distinguished
by its opposite. The one who feels pain deeply is more capable of
experiencing joy. And personally, if you were to ask me about pain, I
should say that if there was no pain life would be most uninteresting
to me. For it is by pain the heart is penetrated, and the sensation
of pain is deeper joy. Without pain the great musicians and poets and
dreamers and thinkers would not have reached that stage which they
reached and from which moved the world. If they always had joy, they
would not have touched the depths of life.

There is the sun and there is the moon, there is man and woman, there
is night and there is day. The colors are distinguished by their
variety and so are the forms. Therefore to distinguish anything there
must be its opposite; where there is no opposite we cannot
distinguish. There must be health in order to distinguish illness; if
there were no health and only illness then it would not have been
(distinguished as) illness. ... Life is a puzzle of duality. The
pairs of opposites keep us in an illusion and make us think, 'This is
this, and that is that'. At the same time by throwing a greater light
upon things we shall find in the end that they are quite different
from what we had thought.

Seeing the nature and character of life the Sufi says that it is not
very important to distinguish between two opposites. What is most
important is to recognize that One which is hiding behind it all.
Naturally after realizing life the Sufi climbs the ladder which leads
him to unity, to the idea of unity which comes through the synthesis
of life, by seeing One in all things, in all beings.