In the beginning God walked and talked with Adam and Eve without any hindrance. God is holy and they were innocent, but they doubted Him and committed the first human sin. This act separated them and all their descendants from fellowship with God, because sinners cannot live in the omnipotent presence of God's holiness. God made a promise that One of their descendants would restore this broken relationship.
However, before He came, the earth was almost completely populated by unbelievers. God saved the only believing family and drowned all the rest. Later, He scattered their descendants with different languages. He called one of these people groups as His "Chosen People" beginning with a man who believed Him, named Abram. After a few generations his descendants forgot who God was and ended up as slaves in Egypt. God chose Moses to deliver them and teach them about the God that chose them and the Law He gave them explaining how to correctly worship Him. This Law was essentially a description of His holy essence and so was a standard to which sinners could not perfectly obey. Fortunately God made them a temporary provision. By faith through animal sacrifices and rituals He forgave their sins until the time that the ultimate sacrificial Lamb of God would come to deliver them from, and trade their guilt for His righteousness, thus restoring their relationship with God in preparation for when they would eternally converse face-to-face with Him in heaven.
The Creator and Owner of all creation gave the newly formed nation of Moses' followers the Promised Land, an area from the eastern coast of the Mediterranean Sea to the Arabian Dessert so that they could enjoy a blessed life as they worshiped Him the way that He had intended. However, within a couple of generations, the people progressively ignored, rejected, and eventually forgot the God that had gathered, saved, and blessed them. So after many events of oppression and subsequent delivery, the brief rise and fall of a glorious empire, and numerous warnings from His prophets, the Israelites were killed, enslaved, and scattered to distant lands.
Then God led a remnant back to Jerusalem where they futilely attempted to regain their former glory. Eventually the Romans dominated them. During this time the first family's promised Descendant lived humbly, died humiliatingly, and arose gloriously to ascend triumphantly through the clouds to heaven's throne while promising to return with true justice and to retrieve His followers. The only stipulated and acceptable qualification for salvation is that these followers respond appropriately to the Holy Spirit's invitation for them to trust the vicarious atonement afforded them through Jesus' death on a cross, burial, and resurrection.
Following this, all true regenerated believers enter into the process of sanctification whereby yielding their entire lives to the work of the Holy Spirit, they are progressively transformed into Christ's likeness. This adventure is punctuated with satanic attacks that are used to test their faith. The believers rely on the Holy Spirit's indwelling presence as they struggle to overcome evil, temptation, and sin. This conflict promotes the spiritual maturation process until they are relieved of sin's molestation at the time of their first and only death, to live eternally blessed. In contrast, the unbelievers will experience a second (eternal) death to suffer a horrific never ending condition of always dying.
The objective of the Biblical narrative is for God to forever enjoy unhindered fellowship with His prized possession - You! This evangelistic message is called, "The Gospel" because it is the best of all good news.