There is no way you can change everyone in this world to your way of thinking. It is not even desirable. If everyone agrees with you, the world will soon run out of ideas. There are many ways of correcting a person when he is wrong. By criticizing, blaming and railing at him in public, you will be humiliating and not correcting him.
Criticism is certain to make more enemies.
If you can show concern for a man's future good with kind words, he will thank you for it someday. Never use harsh or unpleasant words whenever you express your views on issues. Diplomacy, gentleness and politeness do not hurt anybody. In fact they will open many doors. Do not feel defensive when your own faults are pointed out.