In the Bible, "the word of God" or "of the Lord" often refers to a command or message from God to the prophets and others (e.g. 1 Chronicles 17:3), and to his laws and precepts (Isaiah 40:8; Psalm 56:4 and 10). This is rather similar to the way we might say "The Lord is telling me, calling me to ..." etc in response to our prayers and waiting upon him.
The Bible therefore speaks to us with authority, because it contains (among other things) the written record of these "words from the Lord". Nevertheless, on hearing certain passages of Scripture read in church, some people have been known to add "I don't think so" under their breath or even out loud when they have heard that these are "The Word of the Lord". This is understandable when we are faced with accounts of ethnic cleansing (e.g. in the books of Joshua and Judges) apparently at God's command. Similarly some of St Paul's writings, especially about women, are difficult for us to accept nowadays. We also know that slavery and apartheid have been justified in their time on the grounds of "the word of the Lord".
There are two extreme reactions to this problem. One is to deny it exists and to say every word of the Bible must be accepted at its face value. The other is to ignore the uncomfortable bits, adopting a pick-and-choose attitude. Both of these create more problems than they solve.
The fact is, the Bible is a complex book and it cannot be used uncritically. We need to be aware that the issues addressed 2000 years ago are not necessarily the same as those of the modern world. For example, the position of slaves in the ancient world was very different from that of the African slaves on 18th century plantations in America. We can accept that the ancient Israelites thought they were doing God's will when they wiped out their enemies but we can ask whether they were mistaken. To describe such incidents as "the word of the Lord" invites us to repent of the misuse of religious feelings throughout the ages.
The Bible can indeed mislead if it is used uncritically, especially if people simply read it on their own. Many sects and cults have come into being that way. The Bible is in fact the Church's book and any mature reading of the Bible needs to take account of the interpretation, scholarship and prayer which have gone before. In other words, to live out our faith, we depend on a combination of Scripture itself, the Church's tradition of interpreting and applying God's word, and our own God-given intelligence as we ponder what the Bible is saying to us.
But we are left with the fact that the Bible (Old and New Testament) is like no other book. It is a sacred book that has sustained the faith of Jews and Christians for centuries. That faith, though, does not depend solely on the Bible itself but also on our experience of God in prayer and sacrament, and our encounters with others who are hearers and doers of the word.
The conclusion from this is that the Bible contains the word of the Lord but it is not the whole sum of his word to us. The Bible reveals the word of the Lord but it is not the only way God chooses to reveal himself. The Bible nourishes our faith but it is not the only food he gives for our souls.
PMP