Bodhidharma, the famous monk who during the 5th or 6th century AD brought Buddhism to China, said in his teaching that the essence of it all was not to grasp. Just don't grasp -- and you're where you need to be.
What does not grasping mean? It means relaxation. Allowing. Withdrawing. Letting go of effort. Letting go of intention towards everything -- towards the outside world, and just as much towards one's own state of mind. It is, in the parlance of Vedanta, surrender.
Why is it important? When you do not grasp, you give up as much as possible the efforts that keep the mind running in its usual way. The mind grows quiet. In the quiet mind the Self is clearly reflected.
Is it the same as acceptance? I think not. Acceptance implies an affirmative act: a willingness, an accommodation, a giving up of hatred or desire. Not grasping does not do those things. It allows hatred to be where it is and desire to be where it is. It does not grasp them -- nor does it grasp the need to reconcile, accept, or forgive. It lets them all go.
It must be admitted that not grasping -- for the seeker -- does grasp at one thing. It grasps at itself. It does require effort -- minimal, but still significant, crucial -- to not grasp, to surrender. As a seeker one still feels "**I** surrender." And that feeling of doership means the feeling of effort.
So why not "not grasp" "not grasping" itself? This is precisely what the Self does, in fact, and is always doing. The Self does not bother whether one surrenders or not, whether one is ignorant or not, unhappy or not. It is serene and itself in all situations.
From the seeker's standpoint, however, ignorance and unhappiness are precisely what is unacceptable. While in the end it turns out that these are illusory, imagined problems -- until one sees that, one must pretend that they are not. The seeker must grasp not grasping.
Do not grasp anything but not grasping. Surrender all but surrender itself.