In Christian parlance, the expression "dead to the world" probably means having forsaken the pleasures of sinfulness. In the church the word "world" very often denotes the sinful realm or existence, whereas the state of the Christian is somehow other worldly or segregated from the world at large. Being dead to that world then metaphorically means having separated from sinfulness.
Interestingly, in our vernacular, "dead to the world" has another connotation. If a person, say a drunkard, is said to be dead to the world, it means that he is unconscious or unaware of what is happening around him. He is oblivious to reality, being lost in a state of ignorance or even stupor. In a real sense, I believe that as professed believers in Christ many of us are truly "dead to the world" in this sense. The more we strive to be "dead to the world" in the sense above, the greater becomes our unconsciousness to what is actually real and true and consistent with Jesus and His message.
Throughout human history, God has consistently and relentlessly operated through human experience to demonstrate what is true and brings life. Each new war, each new tragedy has provided the occasion to witness both the very best and the very worst of which mankind is capable. On each occasion the observers have been called to make a decision about what this paradox means. When does man act in accordance with his essential nature, when he is noble or when he is beastly? Who deals appropriately with personal suffering, those who fight and resist or those who accept and submit? Of course, the tendency to react to every unpleasantness by struggling and fighting is at the very core of human warfare. It also forms the basis of much church doctrine.
It is difficult to internalize the idea that fighting is not the proper way to overcome what is wrong with the world. However, after every war ever fought, the combatants always ask the eternal question: why did we have to kill one another and what has been gained by it? Later generations and their historians inevitably provide some noble justification, but that explanation is formulated away from the battlefield and all the horrors which caused the participants to question its essentiality and nobility in the first place. The glory of war exists for the most part only in the minds of those who have never experienced that glory. Some may proudly speak of feats of combat, but for the most part warriors do not revel in their combat experience.
Maybe, in our longing for fulfillment and happiness, it is time to wake up from our "death to the world" and seriously consider the life lessons we have seen. If we seek nobility of spirit, peace, and fulfillment, will we ever find that in eternal conflict and struggle? Some may think so, but does human history support that? What are the true lessons of the human experience?
The church is supposedly God's instrument on earth, leading mankind to the truth, bringing life out of death through its message. A part of the new life is a supposed "death to the world" as explained above. Maybe, instead, we are called to relinquish our "death to the world" rather than embracing it. Certainly, given the overall results of attempting to "die to the world" in the church's normal sense, we can rightfully look for something different, perhaps something more consistent with the counter intuitiveness of "love your enemies" and "overcome evil with good".