We are our own worst enemy...

The soul is first born into the false self, it is blind; in the true self the
soul opens its eyes.

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 lions could not harm Daniel because of the harmony of his will with the
universal Will. The lions represent the destructive elements in the human mind.
They represent wars, disappointments, rivalries, jealousies, envy, passions, and
so forth, in different horrible guises. Our ego is the lion of lions, and if
this is conquered, then these external lions -- different egos around us -- are
conquered also, and wherever we go, with anyone, whether foolish or wise, good
or bad, we now have peace.

The work of the spiritual man is to forget his false self and so to realize the
true self which is God, and this true self not only in him, but in his neighbor
also.

Man struggles with things that are outside him, and so he gives a chance to the
foes who exist in his own being. Therefore the first thing necessary in life is
to make peace for the time being with the outside world, in order to prepare for
the war which is to be fought within oneself. Once peace is made within, one
will gain by that sufficient strength and power to be used through the struggle
of life within and without... Life is one long journey, and the further behind
we have left our self, the further we have progressed toward the goal. Verily
when the false self is lost the true self is discovered.