Well without the words from the Bible, we wouldn't know that Jesus came to save us, and said to us, believe and you shall be saved. So yes it was very necessary for a person to be saved by God's very own words. God will speak to us in many ways, Spiritually, through audio, but mainly through the Bible. the Bible is God's guidance, and instructions to the amazing plan he has for us. So yes the Bible is necessary for a person, so we can delve deep and to understand God and see what great plans he has for us.
without the Bible, is like saying without an engine to a car. For the car to move, to work, you need an engine. So its necessary to have the engine for the car to work and move. Without the Bible, is like saying without batteries for an MP3 player, for the MP3 player to play your songs, you need batteries. So again its necessary to have something to make things work. Without the Bible we cannot know the real Creator.
To be saved? we need to Bible for instructions. All God wants is our belief, thats it, not works, not do this or that, as most religions want. God just wants you as you are, and believe in him, just that one word, Believe!.