The 1689 Baptist Catechism asks, very sensibly if somewhat archaically, "What things are chiefly contained in the Holy Scriptures?" It answers "The Holy Scriptures chiefly contain what man ought to believe about God, and what duty God requireth of man".
Firstly, bad because this puts all the emphasis on what human beings are to do with Scripture, which becomes essentially a pot out of which we can draw goodies, rather than the locus of God's powerful communication. We will not be surprised if the rest of the catechism relies heavily on proof-texting, and indeed it does.
Secondly, bad because it makes God inactive and man active. Man has duties; God is merely assigned facts which ought to be believed about him. One would expect from this answer that there would follow a series of questions about God in the abstract. Lo and behold, we move on to "What is God?" (answered with a fairly standard list of attributes which an enlightened pagan could happily endorse), "Are there more Gods than one?" (er, no), and then via the Trinity to the decrees of God. This is a very static, abstract picture of God.
Thirdly, bad because in this context belief sounds like just another one of those duties which God requireth.
I'm trying to come up with a better answer. Something like...
The Holy Scriptures chiefly contain God's witness to his powerful revelation in Jesus Christ, his saving action in human history, and his purposes for each human being, all which we are called to embrace by faith and in joy.
Got a better one?