Our greatest enemy is ourself...

Verily, he is victorious who has conquered himself.

Bowl of Saki, by Hazrat Inayat Khan

Commentary by Pir-o-Murshid Inayat Khan:

Our greatest enemy is ourself. All weakness, all ignorance keeps us from the
truth of our being, from all the virtues hidden in us and all perfection hidden
in our souls. The first self we realize is the false self. Unless the soul is
born again it will not see the kingdom of heaven. The soul is born into the
false self; it is blind. In the true self the soul opens its eyes. Unless the
false self is fought with, the true self cannot be realized.

The soul is a bird of paradise, a free dweller in the heavens. Its first prison
is the mind, then the body. In these it becomes not only limited, but also
captive. The whole endeavor of a Sufi in life is to liberate the soul from its
captivity, which he does by conquering both mind and body.

If a man has control over himself, he will smile and be patient even if he is
exposed to rages a thousand times. He will just wait. He who has spiritual
control has great control; but he who has it not can control neither spiritual
nor physical events. He cannot control his own sons and daughters, for he never
listens to himself first. If he listened to himself, not only persons but even
objects would listen to him.

There is a poem by the great Persian poet Iraqi in which he tells, 'When I went
to the gate of the divine Beloved and knocked at the door, a voice came and said
-- Who art thou?' When he had told, 'I am so and so', the answer came, 'There is
no place for anyone else in this abode. Go back to whence thou hast come'. He
turned back and then, after a long time, after having gone through the process
of the cross and of crucifixion, he again went there -- with the spirit of
selflessness. He knocked at the door; the word came, 'Who art thou? ', and he
said, 'Thyself alone, for no one else exists save Thee'. And God said, 'Enter
into this abode for now it belongs to thee'. It is such selflessness, to the
extent that the thought of self is not there, it is being dead to the self,
which is the recognition of God.