A spirit body is, according to The Church of Jesus Christ of Latter-day Saints, the organization of the spiritual element, made into the spiritual form of man, which was made in the same likeness (shape and form) of God the Father. This likeness (shape and form) apparently gave rise to the phrase and meaning of, "like father like son," which means the son is in the likeness of the father, which provides meaning to the claim that humanity was made in the likeness of God. Generally, people in the world have commonly used the word "soul" to denote this spirit body.
When a spirit body enters into the mortal body and framework through the process of mortal birth, a temporary joining occurs, creating what is called a "soul." Upon mortal death, the spirit body of a person leaves the mortal body and returns to the spiritual realm to await the resurrection. The resurrection is where God raises the mortal body the spirit personage had lost in mortal death, and converts the mortal body from flesh, bone and blood, into immortal bodies of flesh and bone, then rejoins the two, never to be separated again. This is the meaning of the scripture "...It is sown in corruption; it is raised in incorruption:" (see "incorrupt") (1 Corinthians 15:42 - King James / see First Epistle to the Corinthians)
The Church of Jesus Christ of Latter-day Saints teaches that all things created for this Earth, including humanity, had a pre-existence or pre-mortal origin. This means that each person, animal, insect, plant and the earth itself, was first made in the spiritual realm in the same form in which they exist on this mortal earth. This doctrine of pre-mortal existence, the manner of how mankind existed before entering mortality, is one of the important doctrines of the Church, and is believed to support the existence of separate and distinct personages as seen within their doctrine of the Godhead (Mormonism). To begin to understand this teaching, an explanation of "spiritual element" is required.
Joseph Smith, founder of the Latter Day Saint movement, taught that "There is no such thing as immaterial matter. All spirit is matter, but it is more fine or pure, and can only be discerned by purer eyes; We cannot see it; but when our bodies are purified we shall see that it is all matter." This spirit matter always existed and is co-eternal with God. It is this spiritual matter that makes the Holy Ghost. This spiritual matter is also called "intelligence" or the "light of truth." God the Father organized the "intelligence" to make personages or "spirit children," which includes Jesus Christ. (This shows to support the general belief of Christians that all humanity are all brothers and sisters.)