When the others would see this, they would allow themselves to be circumcised too. And that is what Avraham did. In that way, he could have used his tremendously strong influence to persuade them. For it was Avraham's strength of speech alone that had brought so many under the wings of the Divine Presence. It was through the power of Avraham's persuasion, the power of the spoken word, that so many had converted.
Actions speak louder than words.
It would be well to remember that behaving like a mensch can bring someone close to the Torah more than thousands of words of intellectual proof. If you want people to follow , you have to go first. When we look at the situation today, it's easy to despair. The strident metallic clang of materialism and selfishness seem to swamp out the message of the Torah and its People. The sensuous siren call of the media surrounds us all with a world whose reality is merely virtual.