I believe that everything in the Bible is to believed. This isn't to say that everything is factual. There are times when the Bible uses metaphors and parables in order to convey God's truths to us. How to know when to take something literally and when to see it a metaphor? Just look at the context.
For instance 1 Peter 2:4-5 states: "And coming to Him as to a living stone, rejected by men, but choice and precious in the sight of Gd, you also, as living stones, are being built up as a spiritual house..."
Obviously here Peter is using metaphor, not saying that the physcial make up of the church is the same as a rock, but that the church has the strength and enduring quality of stone.
But here Peter says, "Keep your behavior excellent among the Gentiles, so that in the thing in which they slander you as evildoers, they may on account of your good deeds, as they observe them, glorify God in the day of visitation." (1 Peter 2:12) Now, this passage isn't at all metaphorical, we are to take Peter at his word here (understanding the inspiration of the Spirit) and to keep our behavior to the highest of standards.
I bring this up because there seem to be two common problems with how people view the Bible: Some view it as only metaphorical and reject anything literal about it, which means that things that ought be taken seriously by the Christian aren't. The other is that some take things too literally and refuse to see that metaphor and parables are incorporated in the Bible, and therefore take some things too seriously, causing unnecessary strife.
As far as being told to be enriched by the Bible is 'dangerous', nope! To the Chrisitan it holds words of life. We should view it as a well of life-giving water and to drink often and long from it.