Attachment
Ultimately, attachment is caused by desire and fear,
desire for the good and fear of the bad, desire for pleasure and
fear of pain, desire for life and fear of death. If you examine
fear and desire you'll see that fear itself is based on desire,
fear of death is desire for life, and that its opposite, fear
of life, is desire for death. The desire is there because of the
absence of understanding. What will free us from attachment is
understanding, or knowledge of how things really are. So we could
say that attachment is based on fear and desire, fear is based
on desire, and desire is based on the lack of understanding or
ignorance. If we are ignorant, we end up being attached. We are
ignorant of the actual fact that union is about the absence of
boundaries. We create more boundaries with our attachments, which
then stop us from getting exactly what it is we think we want.
(Diamond Heart Book 2, pg 47)

Attachments necessitate objectification; there has
to be an object to be attached to, and by its very definition
there is a loss of the oneness. When we see this we can see that
even God becomes objectified and an object of attachment. If you
look at your usual experience, everything in it is an object,
and you are attached whether you like it or not. If you like something,
it's a positive attachment, you're holding onto it. If you don't
like something, it is a negative attachment, you're pushing it
away. There is attachment in the rejection; by trying to push
something away you're trying to hold onto something else in yourself.
This is the external manifestation of attachment, what it looks
like from the outside. But these feelings of wanting are not what
the actual attachment feels like. You might feel that you can't
let go of someone or something, that you love it, that you would
feel a great loss if it were gone. Most people can only focus
on the object of attachment; if they really saw the attachment
itself they would start falling out of love. (Diamond Heart Book
2, pg 48)

Attachment and essence
Attachments to Essence or some of its aspects cannot
be ignored, especially not in the Diamond Approach. This attachment
will be revealed naturally as a contraction or a restriction.
The purity of Essence and the process of its expansion will expose
it as such. The individual will not be able to be attached and
still experience Essence freely. Attachment is personality, and
it will manifest as a conflict that leads to suffering. In fact
the more Essence is manifesting, the more this conflict will be
obvious. Essence will reveal the attachments. There will emerge
a specific essential aspect whose particular effect on the individual
is to expose these attachments. There will also emerge other essential
aspects that will give the understanding that will specifically
lead to nonattachment, to the freedom from all attachments. (Essence,
pg 153)

Attachment and identity
We usually identify with our self-image; we think
that's who we are. This question of identity with what we think
we are is at the root of attachment. What we ultimately want is
to fight for who we really are, to actualize, protect and defend
who we really are. We want to make what we really are permanent
and, depending on our knowledge of what we actually think we are,
that's what we get attached to. In the beginning, identity manifests
as the self-image, and most of humanity seems to be concerned
with this level. Your identity is very much invested in the image,
how things look on the outside, and that's what you're attached
to. The self-image gets fed by myriad attachments ...(Diamond
Heart Book 2, pg 51)

Attachment and suffering
So it is not only that the loss of the object of
attachment will bring suffering; the experiential state of attachment,
itself, is suffering. It is this state of suffering, of negative-merging
affect, that manifests when the object is lost. This explains
the spiritual teaching that attachment is suffering, which is
somewhat different from what most people believe this truth actually
means; the usual belief is that attachment can lead to suffering.
(The Pearl Beyond Price, pg 257)