Judaism is not against arguments, but it is against the wrong type of arguments. Arguing for the sake of truth with mutual respect is encouraged, and in fact, it is what made Judaism what it is today.
When people argue in a sincere manner, 'for the sake of heaven,' they are both interested in arriving at the truth. That means listening to the other side.
One of many lessons that Chanukah teaches us is to be proud of our achievements, while always striving to accomplish more. Most important is not to be discouraged.