First of all because reading the Bible, makes you get to know God better as His Child.
The Bible must be read and studied because it is God’s word to you. 2 Timothy 3:16 states that the Bible is "God-breathed." Do you want to know your purpose in life? From where did you come? Is there life after death for you? After death, what? What is heaven and what are the entrance requirements’? Why does God permit the evil in the world? How can you make "good things" happening for you, and your fellow man?
Every newborn baby need food to grow.
To grow in your spiritual life, and to grow as a Christian, you need spiritual food.
Can you trust the Bible?
The Bible is totally reliable, without error. It is unique among books. The Bible tells us to test the truth found in the pages. Moreover the Holy Spirit will reveal new truth to you each time you read it. Although God can also speak directly to your heart, you need to know His written Word so you can judge whether God is speaking to you, or the enemy is trying to deceive you. So, read and trust the Bible.
There are hundreds of detailed prophecies in the Bible, that is proven today.
These you can check by looking at the historical accounts it records, and by checking the scientific facts it relates. However, you can not argue yourself into the Kingdom. In the end you must trust and obey. God will not love you more because you read the Bible. It's for your own benefit! This is not required to make God love you. He loves you as you are, in any condition. However, because you want to grow as a Child of God, and also wish not to be deceived, you will need to study the Bible which is The Word of God.
To get guidance in your daily life.
God's Word it's like a candle in the dark and helps you knowing which way to go.
God does not change, and neither does our sinful nature, except through the new birth, which validates everything contained in the Bible. Without the new birth, no fact or argument will sway you. The Bible is as relevant for you today as it was when it was written. While technology changes around us, mankind's desires and nature does not change. You find, as you read the pages of biblical history, that whether you are talking about one-on-one relationships or societies, "there is nothing new under the sun." And while mankind as a whole continues to seek love and satisfaction in all of the wrong places, If you want to live life to the fullest as God intended, listen and heed God's written word...it is even more important than eating food!
To know what you believe in.
The Bible has the equipment you need to serve God and His kingdom. To know God better, you must spend time hearing what He has to say. The Bible is His message to you. If you want Him to listen to what you have to say, you should also listen to what He has to say to you. Meditating on it and obeying its teachings will bring success in your life. God’s Word will help you see the sin in your life and help you get rid of it. It is important to read the Bible, rather than read books about the Bible. As long as you use the Bible as your authority, you may use other books as a supplement, and not as a substitute.
Reading and studying the Bible will help you to see beyond the attractive "bait" to the painful "hook" in sinful temptations, so that you can learn from others' mistakes rather than making them yourself.
Do not read the Bible! Study it and apply it! Let the Holy Spirit lead you with your yielded life through Bible study. God's Word is alive! The more you expose yourself to it, the more it will expose itself to you.
To reveal false teachings.
The Bible tells us that in the last days (the time we now live in!) there will be lots of false teachings and false prophets.
There is much false teaching in the world. Prayerfully reading the Scriptures yourself, is the only real defense against being misled. Only when you study and exposure to God’s word can you make out the truth.
The Bible tells us what God is like! This is important before we find out through a personal encounter with Him. To have a wrong impression of God is worship of an "idol" or "false god." We will than worship something He is not!
Be like Jesus!
Our goal is to be like Jesus. How can we get to that goal? (Don`t worry, you got the rest of your life to get to that goal) To get on the way to that goal, you need to focus on Jesus. What is He like? What did He do? What was His character? etc.
The whole idea of being like Jesus can be summed in two sentences:
1. He shall increase (in me)
2. I shall decrease