Abu Umamah related: The Messenger of Allahصَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ said: "I guarantee a house in paradise for one who abandons Miraa' even if he was the right one". [Abu Dawud]
Miraa here means: arguing in a manner that upsets the oponent by showing his mistakes and defects etc in order to belittle him and show his virtue over his opponent.
So, the Hadeeth is to direct Muslims not to use such means that aim only to show superiority of one over another even if what we advocate is correct.