Spiritually Dead - A Biblical Definition

"For the wages of sin is death; but the gift of God is eternal life through Jesus Christ our Lord." (Romans 6:23)
==Adam Died That Day==
When Adam was placed in the Garden of Eden, he was given one single command, do not eat of the Tree of Knowledge of Good and Evil.  He was further told "in the day that you eat of it, you will surely die."  Satan's lie to Eve was a contradiction to this consequence.  "You will not surely die."  Adam was 130 years old when he begat Seth.  We know he was kicked out of the Garden before he had any children.  Yet he lived another 800 years after he begat Seth.  In terms of physical death, Adam did not die "in the day that" he ate of the fruit he was not supposed to eat.  We must conclude, then, that his death was a spiritual death and that this is the wage of sin that is spoken of.
Furthermore, since eternal life through Christ is also spiritual in nature rather than physical, it supports this idea.  So what is spiritual death?  Is it comparable in function and form to physical death?
==Physical Death==
James describes physical death of humans as a body without a spirit (James 2:26).  Others have described this physical death using thoughts not found in scripture as "wholly incapable of responding to external stimuli".  This is both useless in terms of Bible study and functionally innacurate.  A physical body is wholly capable of responding to external stimuli when dead.  It has been shown that a "dead" person (brain has totally ceased to function) can continue in the following processes: homeostasis of multiple chemical and physiological parameters, detoxifying and recycling of wastes at the cellular level, maintenance of body temperature, wound healing, and respiration and nutrition distribution for up to 20 years.
This is beside the point and is well beyond my purpose in this article.
When we stick with the Biblical definition, we see that death is about separation not functionality.  A physical body is dead when separated from its spirit.
==A Functionless Soul==
If we are to accept the definition of a dead spirit being equivalent to a dead body and that a dead body is one that does not function at all, then we come to a problem.  If a dead spirit is one that does not function, it is no different than not having a spirit at all.  The moment we died spiritually we would also die physically because a body without a spirit is dead - in this paradigm.  Yet people who are spiritually dead are still walking around, communicating, functioning, responding to external stimuli on the mental (thus spiritual) level.  Therefore we must reject the definition of spiritually dead as a spirit that does not function.
==Spiritual Death==
In Isaiah 59:2, Isaiah writes by inspiration from God - "But your iniquities have separated between you and your God, and your sins have hid his face from you, that he will not hear."  Paul writes in Eph. 4:18 - "Having the understanding darkened, being alienated from the life of God through the ignorance that is in them, because of the blindness of their heart:".  God is the source of all life.  Sin separates us from God and that separation is what defines spiritual death.  The whole Bible is about man's separation from God and God's plan to reconcile man to Himself.
==Conclusion==
If we use the Biblical definition of spiritual death - a separation from God - rather than man's definition - a cessation of function and inability to respond to external stimuli - then we can accept a few things that the Bible teaches at face value without having to jump through theological hoops.  The most poignant of these for this forum is this:
The spiritually dead person is capable of understanding and responding to the gospel without being regenerated.
The gospel is God's mind revealed to mankind for the purpose of saving mankind. The gospel is God's power unto salvation (Rom. 1:16) it is powerful (Heb. 4:12) and it does not return to God void (Isa. 55:11). We know that faith comes by hearing the gospel (Rom. 10:17) and faith is able to save as a conduit for God's grace (Eph. 2:8) though not alone (James 2). With the proper understanding of what spiritual death is, we can know HOW man is saved by faith and where regeneration takes place without requiring a doctorate in theology and without being indoctrinated by those who have such.
To be saved, the unregenerated person must hear the gospel, believe it, and obey it from the heart (Romans 6:16-18), being then made free from sin and reunited with God, restored to a right relationship with him and given eternal life at that moment, being no longer separated from God.
In Truth and Love.