For God so loved the world, that He gave His one and only Son, that whoever believes in Him shall not perish, but have eternal life.
Since the time we are babies, our understanding is basically made up of what we observe in one form or another filtered through the grid of whatever is hard-wired into our brains, handed down from our DNA. There is also evidence that our personal choices in life can affect what we believe.
As we experience the world, it becomes clear that there are causes and effects. Every child asks the question, "Why?", which moves toward the cause of things. This question is repeated over and over, (often aggravating parents,) until naturally giving rise to the question of Who or what is the Prime Mover.
In all of philosophy, this fundamental question can be boiled down to one of two basic answers: either the universe is self-existent, the naturalist view, or the universe must necessarily have been specially created by God, the supernaturalist view. One's choice of this answer will affect all of the resulting worldview from this point on. How interesting that the first verse of the Bible addresses this very question.
There is an abundance of evidence that the supernaturalist view is correct. Not the least of which is, that scientists observe that the universe appears to be and to have been expanding. This leads many to postulate about a big bang, but really all it necessitates is that the universe cannot possibly be self-existent. Those who avoid or reject this conclusion fret, trying to explain how a big bang occurred, which still does not really explain where it all came from, or fill the empty question, "Why is there something, when, in fact, there should be nothing?"
So then, the most excellent question is "Why?", which points us to God, and the related query "How?" is the same question in reverse, looking down on creation from God's point of view.
We see also that the beautiful life around us seems to have been intelligently designed. The magnificent replicating DNA molecule is so complex, even including machinery to repair itself, that the chances of it coming about by random physical processes is infinitesimally small and for all purposes zero. And, a physical process which increases order out of nothing has never been observed.
It is also interesting to note that a large majority of people in every culture in all of history believe in some form of a God. Sadly, many of the same people today also give some credence to naturalistic ideas such as evolution which are opposed to all our conclusions so far in every way. But, every society has had a set of often strikingly similar moral rules. So, while these things do not mathematically prove God's existence to a certainty, they provide compelling evidence.
Now then, if there exists a God, what can we expect about any communication He may have had with us based on what we know so far? Unlike all other sacred books, the Bible is the only writing which fulfills the criteria according to these expectations. Even its critics are occasionally forced to admit that it is philosophically, scientifically, historically, archeologically, psychologically, and prophetically accurate beyond any mere human explanation. There is a saying: "Every time the archeologist's shovel hits dirt in the holy land, it buries another Bible critic."
Then, there is the appearance of one perfect man. Most scholars agree that the most influential man who ever lived is Jesus Christ. This fact alone is enough to warrant a second, deeper look at His life and teachings. Jesus claimed to be God and the only way to God. Is He liar, lunatic, or Lord? One-time critic and famous 19th-century law professor Simon Greenleaf, whose work is still in use today, after having been challenged by students, finally concluded that there is more evidence, including third-party evidence, to legally "convict" Jesus of having risen from the dead, than most other "facts" of history, even more for example than that an emperor named Julius Caesar ever existed. If Jesus had the power to raise Himself from the dead, then He is Lord.
And in my own life, too, I believe I have seen God answer prayers many times.
The Bible, then, can be summarized in the following 7 points:
1. "In the beginning God created the heavens and the earth", originally perfect and beautiful. - Genesis 1:1.
2. Man sinned against God. The original creation is still beautiful, but now faded; this agrees with what we see. "To Adam he said, 'Because you listened to your wife and ate from the tree about which I commanded you, "You must not eat of it," Cursed is the ground because of you; through painful toil you will eat of it all the days of your life.' " - Genesis 3:17.
3. God has a holy law for us, "You shall have no other gods before me." - Exodus 20:3, and we "have been weighed on the scales and found wanting." - Daniel 5:27. The New Testament agrees: "for all have sinned and fall short of the glory of God, ... For the wages of sin is death". - Romans 3:23, Romans 6:23.
4. "For God so loved the world that he gave his one and only Son, that whoever believes in him shall not perish but have eternal life." - John 3:16. Jesus died on the cross for our sins to forgive us. "That if you confess with your mouth, 'Jesus is Lord,' and believe in your heart that God raised him from the dead, you will be saved." - Romans 10:9.
5. Those who have accepted Jesus' salvation are now urged, "in view of God's mercy, to offer your bodies as living sacrifices, holy and pleasing to God-- this is your spiritual {or reasonable} act of worship." - Romans 12:1. We should also forgive one another.
6. Even our faith is a gift from God. "For it is by grace you have been saved, through faith-- and this not from yourselves, it is the gift of God-- not by works, so that no one can boast. For we are God's workmanship, created in Christ Jesus to do good works, which God prepared in advance for us to do." - Ephesians 2:8-10.
7. After we die, each one of us will go to either Heaven or Hell. "If anyone's name was not found written in the book of life, he was thrown into the lake of fire. Then I saw a new heaven and a new earth, for the first heaven and the first earth had passed away, and there was no longer any sea." - Revelation 20:15, Revelation 21:1.
(All scriptures quoted from the NIV.)
All things are from and to our Lord Jesus Christ, to Whom is all glory due forever.
For more information on how to be saved, read my short paper, The Essentials.