Knowing who God is, and responding appropriately, is the most important thing in our lives. Proverbs 1:7 says, “The fear of the Lord is the beginning of knowledge.” You might even question if there is a God. I'll be honest with you, we aren't even going to grapple with that question, and here's why:
“18 For the wrath of God is revealed from heaven against all ungodliness and unrighteousness of men, who by their unrighteousness suppress the truth. 19 For what can be known about God is plain to them, because God has shown it to them. 20 For his invisible attributes, namely, his eternal power and divine nature, have been clearly perceived, ever since the creation of the world, in the things that have been made. So they are without excuse. 21 For although they knew God, they did not honor him as God or give thanks to him, but they became futile in their thinking, and their foolish hearts were darkened. 22 Claiming to be wise, they became fools, 23 and exchanged the glory of the immortal God for images resembling mortal man and birds and animals and creeping things.” 
The fool says in his heart, “There is no God.”
The question is not, “is there a God?” He has made that clear. The question is, “who is He?”
Why we need the Bible
This leads us into our study today. How do we answer this question of who God is? You may have noticed that three times already I have referenced the Bible. That should give you a clue as to where we're going. The reason we must approach the Bible to know God is that it [the Bible] is God's revelation of Himself. Other religions and systems attempt to seek knowledge of God via other means. Means which, invariably, fall woefully short of true knowledge of God. Why is this? It is because, “God makes himself known on his own terms, when, where, and how he chooses. God can be an object of our knowledge only if he has revealed himself to us. Consequently, theology can exist as a legitimate enterprise only when it begins with God's self-revelation.”
What makes us think the bible is God's self-revelation? Well, there are many places we could turn, but let's look simply at one of them.
“20 knowing this first of all, that no prophecy of Scripture comes from someone’s own interpretation. 21 For no prophecy was ever produced by the will of man, but men spoke from God as they were carried along by the Holy Spirit.”
The men who wrote the bible did so as the were carried along by God, and thus they spoke the very words which He wanted them to speak. This wasn't some sort of mechanical dictation, as you can see from the many styles and personalities of the writers which come through, but this is no mere human book. This book is the word of God Himself. In looking at the bible we will cover four main points, which you can remember with the acronym “SCAN.”
S- the bible is Sufficient
C- the bible is Clear
A- the bible is Authoritative
N- the bible is Necessary
Now, while SCAN is a handy way to remember these four points, I believe we will be better served if we walk through them in reverse order.