One of Michel Cimino's great lines in the movie "The Deer Hunter" was delivered to the character Stanley at the beginning of the hunting trip after the wedding. Sitting on the hood of their car up in the mountains, Cimino pulls a rifle cartridge from his pocket and holds it up to Stan, saying, "Stanley, see this? This is this. This ain't something else. This is this." That line captures the essence of acceptance. This is this. Things are what they are, and no amount of pretending will make them otherwise.
As long as we remain under the spell of the filters we were given as young children, it is very difficult to see things as they are. The filters mask the real nature of things, and we see them largely as reflections or projections of our own internal states. Discarding the filters helps us see outside objects, events or situations more clearly. Of course, in order to discard our filters we must first understand what they are and how we acquired them. The inner inquiry into the origins of our filters as described under "Trust" is the key to this process.
Clarifying our perception is only the first step in acceptance, however. In order to truly accept the universe as it is, we need to respond to it authentically. It is of little use to understand that "This is this" if we then say, "Yes, but I it should be that, because the fact that it's this makes me uncomfortable." That reaction comes from the programmed patterns that we inherited at the same time that we got our perceptual filters. To complete our journey of acceptance we must be able to respond to the clearly seen universe as it is, not as we would prefer it to be for one reason or another. Fortunately, the same journey of inner inquiry that reveals our filters also allows us to investigate the origins of our programs, and becoming aware of them likewise loosens their hold on our behaviour.
The ability to see things for what they really are, and respond to their true nature is true acceptance. For example, imagine being stopped by a red traffic light. It helps our acceptance if we can realize that it's just a traffic light rather than something put into the universe by malevolent fate to impede our personal journey. It helps even more to then realize that our impatience is an automatic response that stems perhaps from a fear of being late that was generated by a traumatic incident when we were three years old.
Out of such mundane stuff comes our ability to accept things as they are. This ability to accept is yet another manifestation of our improving alignment with the universe.