Mankind, Humanity or simply Man, is a special creation of God in His image, alongside the land animals on the sixth day of Creation. Created to be in communion with God, the original couple was charged with the care of the earth and all life thereof. This agreement was part of the first Covenant to be made between God and mankind. In taking care of the earth, mankind was to refrain from eating from just one tree among all that had been provided for food.
Originally a perfect representation of God's creative genius and power, mankind fell from perfection by willfully disobeying God by eating from the forbidden tree. This changed the basic nature of innocence to one of a tendency towards sin. This tendency is what is known as Original Sin, and is part of every person ever born apart from Jesus Christ. The consequences of this was mortality--everybody born to the couple would eventually die.
Since then, humanity has been in rebellion against God. Original Sin has made it impossible for mankind to come close to God on its own. Essentially selfish, mankind has sought to live apart from God's guidance. However, the Creator had a purpose for His image bearer and made sure that it did not die out. A series of agreements were made with chosen representatives of mankind to provide a way to once again commune with God.
Mankind became split into two groups--the children of God and the children of the world. The problem of sin would lead everyone away from God, but He made a way for His children to follow Him. These two ways lead to either death or a special kind of life with God. That life with God will, in the end, be in special bodies made to live forever.
The word Man (Heb: Adam) is from a word meaning "red", reflecting the color of the ground (Heb: adamah). Another word for "man" was esh or enos, a term reflecting the relative weakness of mankind among the animals. The first man, Adam, would use a play on this word to classify his new mate as an issha, or woman.
In the Greek language, the generic term for mankind is anthropos ("man-faced). The specific term for a male of the species is anér or adros. The term for woman is guné. The specific terms are also used for "husband" and "wife".
Mankind began on the sixth day of Creation when God determined to make the species of special animal to be like Him in a spiritual and mental way. Though all other living things were also made from the elements--dirt and water--a special care was taken in the making of mankind. The Creator entrusted the upkeep of the earth to this new species, promising great blessings if this trust was kept.
Mankind, in the person of the first couple, failed to stay faithful to that trust, willfully disobeying Yahweh at the instigation of Satan who appeared in reptilian form. As a result, the original agreement, a Covenant of Works, commonly known as the "Adamic Covenant", was broken. As per the agreement, mankind would begin to suffer to the point of death.
However, Yahweh showed mercy on mankind, allowing them to live for a long time, though not forever. Before expelling Adam and Eve from the garden, God first hinted at a way out. He mentioned in cursing the serpent that the "seed of the woman" would crush the head of the adversary. In providing skins for the two of them, a second agreement, a Covenant of Grace was sealed. This covenant would be confirmed with chosen members of the race.
Main article: Great Flood
The first grace period, under Adam and his children, lasted for over 1600 years. But even with a godly line after a tragic split of the linage at the murder of Abel, only one man and his family were found to save the world from total destruction. This man was Noah. God looked in favor upon this man and instructed him to build a large boat to save all life on land, including the birds of the air. After a century of warning, mankind was to suffer almost complete extinction.
As Noah and his family were worshipping God after the flood, He made the first full covenant with the remnant of mankind: He would not destroy mankind with a flood ever again. The decree to spread out an inhabit the planet was renewed. Mankind was told that life was precious, but he was to be allowed to kill animals for food, but without the blood. Murder became a crime for the first time. The sign that sealed this covenant was a rainbow in the sky. This is known as the Noachian Covenant
Main article: Tower of Babel
Mankind failed to trust God again after the flood. This time the descendants of Noah came to a group decision to stay together rather than scatter. In doing this, they showed they did not trust God to lead them. Cities were built and a fortress was constructed to serve as a temple reaching into the clouds.
As a result of the presumptive behavior, God stopped the work on the tower, created languages and dispersed families and tribes in all directions. By this action, mankind began divergent paths through time via descendants of Japheth, Shem and Ham. After a fresh start, it became necessary for God to find another person to continue a godly line. He chose a man from the tribes that descended from Shem. This man, by the name of Abram, would be called out from among people worshipping false gods.
Renamed Abraham, this man became the "father of the faith". It was through him that the promised savior would come. This third covenant, the Abrahamic Covenant would be the basis of New Covenant when the Savior would come to fulfill the next two covenants. Part of this agreement was a temporal land that would be typological for a worldwide kingdom of the children of God. However, it would be about 800 years before that land would become a nation. The seal of this covenant was Circumcision, a symbolic sacrifice of a bit of skin and blood.
The promise was continued to Abraham's son Isaac and his grandson Jacob while they continued to wander in a foreign land. One of Jacob's sons, Joseph would become a leader in the land of Egypt, a great nation from the line of Ham. While there, a descendant of Jacob named Moses would be used to bring the Israelites out of Egypt and to the land of Canaan. His chief of staff, Joshua (Son of Nun) would lead the conquest of that land after Moses died. The Law would be given to the people as they traveled from Egypt to Canaan. This is known as the Mosaic Covenant. The seal of this covenant was the observance of the seventh day as a Sabbath.
For a period of about 400 years while neighboring kingdoms were weak, the Kingdom of Israel arose with a great king by the name of David. Near the end of his reign, Yahweh made an agreement with him that there would be a member of his dynasty ruling God's people for as long as the nation existed. Beyond that, a special king, the promised Messiah would arise to fill the place of power forever. This agreement, known as the Davidic Covenant]], was sealed by the building of the Temple to replace the Tabernacle as a place for worshipping God.
All of these covenants had become promises to a small segment of mankind. Great leaders had risen and fallen among the children of the world, but their empires paled to the kingdom of God, also known as the Kingdom of Heaven. The greatest king of them all would not be over a people group, but would be the ruler of a worldwide kingdom. The King would be a descendant of Adam, Abraham and David. He would also be the Son of God in a unique way. As such a new agreement would be made for the sake of the children of God. Gone would be the sacrifices of the Law--mere shadows of the reality of the gift of the Life of the Messiah in the place of the sinful mankind.
At His Ascension, Jesus became both the Priest and King of His people, that part of mankind that which followed His Way. This was the fulfilment of the Davidic Covenant as a new "Israel", made up of all kinds of people from all of mankind, spread out to fulfill the Noachian Covenant. The New Covenant would be the last agreement God would make with mankind. Its seal is the rite of baptism with water.
Future of Mankind
Mankind will never become extinct. In fact, even death does not end the existence of a human being. This is because members of the human race are creatures of two realms--the physical and the spiritual. Though physical death claims practically everyone (see Enoch and Elijah), there is a second death coming for all of those who are "children of the world". This death will be when the spiritual existence of life after death becomes exponentially worse. The other part of mankind, that of the "children of God", will experience a time of rest before their spirits are rejoined to new bodies in the Resurrection unto everlasting life.
After Jesus died, his body went through a transformation into a new form. This body is energized by spiritual means rather than the blood that brings life to every cell of the natural body he had received at birth. In this way, Jesus validated his earthly ministry. He showed that the prophecy of Daniel was true--Life continues after death. Furthermore, it validated his promises to his followers that He would not abandon them. The message of the Gospel was very much true.
On the other hand, the children of the world will see a different resurrection. After having suffered according to their deeds in this world, they will be judged further according to those works. The language of Scripture is very hyperbolic concerning the final state of unsaved mankind, but it is clear that it will not be pleasant.
This final judgment will be based on what God knows about mankind. This knowledge is metaphorically presented as two books: the ledger of deeds and the book of life. The first book has the record of everything ever done by mankind. The second book is the "census" report for the Kingdom of Heaven. The names written in the book of life are secure, for those found there have been saved by God from the Judgment due to them. This is because of the work of an intercessor acting on their behalf.