The word accept has many meanings, and the central concept in all of them is that of receiving, or even more generally, willingness to be with something. The “will” in willingness is what makes acceptance powerful. Acceptance is an expression of your will to create inner peace by accepting Reality as it is — right now — in the present moment...
Acceptance is making peace with What Is.
The opposite of acceptance is resistance, which is any thought or belief that opposes Reality. The mantra of resistance is, “Things should be different than they are!” The mantra of acceptance is, “Things are what they are, and All Is Well.” So the shift from resistance to acceptance begins when you release your judgments about the way things “should” be.
Resistance and judgments cause virtually all of the stress we experience. Thus, acceptance dissolves stress. If you want to eliminate stress from your life, practice acceptance.