Defense wins games. Simple. It's the foundation of any strong team, and it comes from three major things: good defensive structures, good defensive techniques, but most importantly a good defense is born out of trust in your fellow warriors. You trust the guys around you to make the tackles, they trust you in the same way, and none of you will let the others down. You'll make the extra effort, you'll bleed and hurt and never, ever take a backward step. Because you are a part of a unit that can be far greater than the sum of its individual parts, simply by believing in each other.
That's the sort of attitude and belief that can make the ordinary team great, and the great teams unbeatable.