OLD TESTAMENT
After Adam and Eve, the Hebrew lineage began with Abraham (around 1900 B.C.).
             Abraham's personal covenant (contract) with God (Genesis 12, 15, 17)
  To seal the deal, God promised Abraham that he would be the father of "many nations," and
  that he and his descendants would circumcise male newborns on the eighth day after birth.
   Abraham had Isaac, who had Jacob (whose name was changed to Israel), who had twelve
sons, resulting in the twelve "tribes" of Israel. Joseph, one of Jacob's sons, was sold into slavery
 in Egypt, forcing Jacob and his family to travel there and their descendants to become slaves.
  Moses led the Israelites out of Egypt around 1250 B.C. and established the Covenant of God
                                       with the Hebrew nation.
          The Hebrew People's (Old Covenant) Covenant with God (Exodus 34:27-28)
  In order for God to be their God, God gave the Israelites the Ten Commandments to follow.
    There were ongoing problems with the Jewish people believing in idols and other "gods."
 Eventually, the Israelites arrived in the Promised Land and lived there after Moses died. Until
   around 1000 B.C., "judges" directed the people. When kings were installed, they were still
 viewed as people doing God's will (rather than as kings of other nations with absolute power).
 King David and King Solomon ruled over a united and powerful realm, which was divided after
                                          Solomon's death:
 Southern Kingdom - known as Judah, but it included both Judah and Benjamin's "tribes"; this
  group included Jerusalem. The Babylonians conquered the Southern Kingdom in 586 B.C.
 The Northern Kingdom, also known as Israel, was made up of the last ten "tribes"; this group
    included Samaria. The Assyrians conquered the Northern Kingdom around 722 B.C.
Despite rebuilding the Temple in Jerusalem in 520 B.C., the Hebrews were never able to regain
                    their strength and were eventually conquered by Rome.
  It was believed that the Hebrew people's hardships and exodus from their native land were
 caused by their worship of idols and pagan "gods" (primarily as a result of marrying non-Jews
 who introduced foreign religions). The prophets—Elijah, Elisha, Isaiah, Jeremiah, and Ezekiel,
  among others—were God's representatives to the people and their authorities; they openly
    disagreed with the individuals in charge and spoke out against idolatry and "false gods."
 Proverbs, Ecclesiastes, and Job all contain nuggets of wisdom. Psalms are poems and hymns
  written by the Hebrew people. In the later scriptures, there was widespread belief in the "last
  days" (of the future around their time or at a later era) and the Messiah who would lead them
                                        with great authority.
 The Old Testament of the Bible is primarily concerned with the time period beginning around
1500 B.C. to 100 A.D. The first five books are known as the Pentateuch (or the Books of Moses;
               or the Torah) and are revered by Jews, Christians, and Muslims.
                        NEW TESTAMENT
Jesus Christ's life (from the virgin birth to His ministry, crucifixion, and resurrection) is
the basis for the four Gospels -- the books of Matthew, Mark, Luke, and John. Jesus
taught to love others as much as yourself and to love God as the one and only God.
Jesus performed many miracles and healings, described the Kingdom of Heaven, and
told people how to live as God wished them to live. Jesus' numerous story illustrations
were used to guide the people with things they were familiar with. Jesus chose twelve
disciples (representing the 12 "tribes" of Israel) to assist Him and spread the Word of
God. Conflict with religious leaders (Pharisees and Sadducees) led to His crucifixion
(death on the cross), which was approved by Roman leaders (At the time of Jesus,
Rome ruled the Jewish people, who yearned for freedom). The death/sacrifice of Jesus
Christ resulted in:
New Covenant (contract) of God with all people (Jews and Gentiles [non-Jews])
1) Written in their minds and hearts
(2) All who believe in Him are forgiven by Jesus Christ's sacrifice (by His blood)
to take away their sins.
Refer to:
      Jeremiah 31:33 (Old Testament reference)
      Matthew 26:28
      Mark 14:24
      Luke 22:20
      Romans 8:3
      Philippians 3:9
      Hebrews 8:10
      Hebrews 9:15
      Hebrews 10:9-10
Which is further described by
John 3:16 -- (from King James' Version)
"For God so loved the world, that He gave His only begotten Son, that whosoever
believeth in Him should not perish, but have everlasting life. "
The requirements for Christians: are given in 1 John 3:23
"And this is His command: to believe in the name of His Son Jesus Christ, and to love
one another..."
After Christ's death and resurrection, Paul became converted to Christianity and
extended the teachings to the Gentiles (Greeks, Romans, and other non-Jews),
accounting for the early, rapid growth of Christianity in spite of great persecution of the
believers. Jesus' death and resurrection and His expected return at the "last days" were
told by Paul. Life after death was described by Paul (1 Corinthians 15:35-58), with a
new, non-earthly body. The Revelation and other writings address the "last days" with
Christians given life in heaven and others given to "the Lake of Fire" (hell).