Surrender
Surrender is a step further than letting go, a small step further.
The letting go is ceasing the activity of resistance. When you
surrender, you realize that you are pushing and resisting, and
then you understand it so that you are not as interested in the
resistance. And then, because you have stopped pushing, a certain
essential state, a certain energy arises and begins to flow. This
flow of energy of the essential state, plus the letting go, the
cessation of activity, is felt as surrender. So surrender is a
meeting of the personality and Essence. The personality does its
work of seeing its identification, its resistance, and its contraction.
That's its part; it can't surrender. Essence comes along and melts
it. The personality can't melt on its own, but it can be melted.
(Diamond Heart Book 3, pg 176)

The issue of getting one's own way is a big one for the personality,
and the thought of surrendering to God's will may seem to involve
giving up your own will. However, if you are sincere and truthful
with yourself, and you stay with your experience without trying
to change it in any way, you find out that having your own way
is really a matter of surrendering to your inner truth. Your way
is following the thread of your own experience. It is not a matter
of choosing or not choosing it; your way is something that is
given to you. It is the road you are walking on, the landscape
you are traveling. You discover that it is a huge relief not to
feel that the territory you are crossing should be different than
exactly how it is for you. (Facets of Unity, pg 130)

Surrender is not resignation. It is very important to distinguish
between them. Resignation means that you are admitting that you
cannot get your own way. You are taking yourself to be a separate
self with a separate will that is being thwarted by reality. This
is very different from true surrender, which is neither acceptance
nor rejection, but ceasing to separate one's own will from reality.
To learn to surrender means to expose your willfulness -- the
belief that you have a will separate from reality's and that you
can have it your way. (Facets of Unity pg 131)

The personality can only perpetuate itself. The moment you try
to do something, you're on the wheel of action and reaction which
is what we call the wheel of samsara. Perhaps to you surrender
means that you will engage in an activity. But the activity of
the personality is a rejection, which is ultimately hope and desire,
leading to frustration. How can that be surrender? Surrender can
only be awareness of activity. When you are aware of that activity,
you're not interested in engaging in it. If you can feel the core
of frustration directly and understand what it is, you are not
engaged in it even though you might be feeling it. And the more
you see it, the more it becomes ego-alien. If you see the activity
and don't go on with it, then the essential state which you've
been resisting will arise and melt away the contraction and reactivity.
What arises is a kind of acceptance and love, which flows and
melts you away. (Diamond Heart Book 3, pg 181)

Surrender and personality
When there is surrender and letting go, there is no activity
and ego is not there. The cessation of resistance, the cessation
of rejection, the cessation of defense, is also the dissolution
of that part of the personality. It may bring fear because you
believe that you will disappear. And you may be concerned about
who will do what is required if you don't do it. You need trust
and confidence in Essence here. (Diamond Heart Book 3, pg 183)