I can't speak for other branches of the military but as for the Marines, this code rings true, through & through. God, Corps & Country, that is the code and for those of you who aren't educated in the ways of the Corps, the Corps is your family. It is a simple code with just three elements. Three simple elements, that run deep in the blood of Marines.
Let's start with God. The Marine knows that his strength does not only come from within but from a higher power. Everywhere you look you'll see marines bowing their heads and taking a knee in their reverence to God. You ask if all Marines are Christian or do they all believe in God. Some don't but most do. Bottom line is that it is part of their code and they will all fight to the death to defend it. If you look at the battles past and present you will see that the Marines are there to fight for the oppressed .
The second part of the code, is the Corps. To the Marine the love of the Corps is nothing but pure family to him. It defines who he is, what he is, and what he will always be for the rest of his life. He takes an oath to defend the constitution and fight enemies foreign and domestic. No one ever relieves him of these duties, therefore it is in his blood for the rest of his life. When I say the Corps is family, what I mean is, for a lot of these Marines, this is the closest they have ever experienced in the way of a family unit (camaraderie). Not just the textbook definition of camaraderie but one that binds ties like family because of everything they go through together. In times of life and death it's the one Marine that saves the other Marine.
Last but not least, the final piece of the code is Country. How the Marine loves his country. This defines who we are, where we came from and where we're going. This is the land that has given us freedom and where our parents, siblings and friends call home. This is the land where we have drawn a line in the sand and have promised to protect it no matter what, even if it means death.
I have always said ever since becoming a Marine, there is NO more proud way to die than to be defending my country. To die in battle defending your nation and the soil you call home is pure bliss. It would be the equivalent of going out in a blaze of glory. A hero's death. God, Corps and Country.
It's a simple code with 3 little elements but one that runs so deep that most will never understand it. Get together sometime with a bunch of Marines even if they don't know each other and you will feel the camaraderie just oozing from the pores of their very skin. It's something most people can't explain nor understand. It's the code all Marines share.