I used to believe that words have the greatest power but with time I have come to realize that silence has its own way of being understood too. There is a disclaimer attached to it though - either the person you are speaking to doesn't matter at all or matters to you the most.
Personally, I have preferred to stay silent in some important conversations of my life. While I have always contemplated if I should have voiced my opinion then, the conviction that its outcome was supposedly better than what could have happened has always stopped me from speaking.
Silence lets us handle the uncertainties in our lives. It lets the other person commit mistakes and understand the situation better. It lets circumstances speak for themselves. It has its own beauty of showing our disagreement too. But most importantly it also stands for acquiescence. Every single permutation and combination of it simply depends on the person it is targeted at. Either he understands it or doesn't but the purpose is not always served.
The probability of being misunderstood is the greatest liability of staying silent.
But we still practice it.
The fact that we have multiple choices in our lives and we are so unsure of choosing the supposedly right alternative that we resort to the one having multiple interpretations is the only logical explanation for our sealed lips.