All Scripture is inspired by God and is useful to teach us what is true and to make us realize what is wrong in our lives. It corrects us when we are wrong and teaches us to do what is right. God uses it to prepare and equip his people to do every good work.
2 Timothy 3:16-17 New Living Translation (NLT)
Several things come to my mind when I consider the Bible as the inerrant Word of God. The main thing is how often I have conversations defending its validity. So many times I have been told that it was written by man and because of this cannot be completely accurate. There are many translations available that cause some to say that they sometimes contradict one another. The reason I use different versions when I quote Scripture is because they all say basically the same thing but are designed to assist in the understanding of the reader. That's where the Holy Spirit comes in to reveal to us the truth of God's Word. Just like everything else, we are not left to our own devices to discern Truth but we have to read it for ourselves to make this connection and believe that God inspired it.
God can use a rock, a donkey and anything else He chooses to speak to us. He took ordinary people and inspired an extraordinary Book for mankind to reference in knowing Him. There is no other Book like the Word of God because Jesus Christ was the Word made flesh. How else would we know Jesus if the Bible had not been God-breathed? We quibble about semantics, but miss the point.
One other thing that comes to mind about the Bible, and this passage in particular, is what it says about how the Bible is to be used. Too often people pick up the Book and use it as a weapon to beat other people up. It does say in the Bible that it is the "Sword of the Spirit." However, I believe this is meant to protect us by giving us knowledge of God's constant presence which is promised in the Word, His ways, His expectations, His help and His love. What this passage refers to is what God expects us to do with ourselves and use the Word to correct our own hearts and behavior, not everybody else's. It also conveys that God is working in each of us.
Read it. It is the one sure way God speaks to us and gives us a glimpse of our future with Him.