Jesus said to them, “Is this not the reason you are wrong, because you know neither the Scriptures nor the power of God?"
The Sadducees were wrong for at least two reasons. Their unbelief led them to approach scripture purely academically. Like present day liberal theologians, they coldly approached the text only with skepticism, quick to explain away anything miraculous. As a result, they dismissed most of their bible. The prophets were spurious and they took a cafeteria approach to the Law and History books, loving the legal aspects but rejecting anything supernatural. Jesus says that a person cannot really know scripture if they dismiss what it says.
This humanistic approach that placed the human mind above the scriptures naturally led them to a powerless theology. When they came to Jesus to question Him on the resurrection (a doctrine they rejected), they thought they had Him stumped with a massive hypothetical conundrum. But Jesus refused to take their illogical question bait, instead going to one of the foundational phrases of the Pentateuch - the one bit of scripture they prided themselves as being expert in understanding. At the burning bush God told Moses, "I am (present tense) the God of Abraham, Isaac, and Jacob", indicating that the patriarchs existed at the time of the meeting with Moses. God is the God of the living. The careful, simple reading of the text and its grammar confirmed this.
Jesus thus affirms an essential component of Christian faith: the centrality of the Holy Scriptures for knowing God. To know God's power and person, we must know the bible. In the scriptures we have life revealed for us. We have insight into this present life and living hope beyond it. We can know God and God's power in its pages. And my experience is that it translates very well into my own moments. The scriptures are not "supernatural" but the God Who is shown to me in them most certainly is. And the faith that springs out of the Word of God daily brings me to know His presence, to trust His person, and to be affected and changed by His power. I always want to know the Scriptures and the power of God!