The Bible always speaks of the second death. Believers experience the first death and the unbeliever experiences the second death.
First there is bodily death. There is a sense, though, in which the body is already dead even before its decisive separation from the spirit. “The body is dead because of sin” (present tense), says Paul. Romans 8:10 refers to the physical death to which the body is already a prisoner. Even though it is presently alive, it is already subject to death, smitten with death, under the curse of death, doomed to die. It is already experiencing the harbingers of death in the form of a multitude of diseases, deformities, infirmities, aches, and attacks.
Then there is the spiritual aspect of death. Man is intended to be a unity of spirit and body. As long as the two are united, the body is physically alive. The presence of the spirit is in some way linked to the life of the body; Jas 2:26 says that “the body without the spirit is dead.” Physical death occurs when the spirit leaves the body (see John 19:30).
For the Unbeliever there is Eternal Death
It is called eternal death because it takes the form of eternal punishment in hell. Jude 13 seems to equate it with “the blackness of darkness” that has been forever reserved for the wicked. Those who are eternally lost will experience this death both in their sinful spirits and in their reconstituted sinful, unredeemed bodies (Matt 10:28).
In the final state the wicked will experience the true essence of death in its full intensity, i.e., an eternal, irreversible separation from God and therefore an absolute absence of life and hope. “Depart from Me” will be among the final words they hear from the Judge (Matt 7:23; 25:41). They will spend eternity “away from the presence of the Lord and from the glory of His power” (2 Thess 1:9). 
 Cottrell, J. (2002). The faith once for all : Bible doctrine for today (204). Joplin, Mo.: College Press Pub.
Published on Tuesday, September 17, 2013 @ 4:30 AM CDT