"therefore"
When Jesus accuses the Sadducees of error (in Mark 12:24), he tells them that the reason they make mistakes is that they don't pay enough attention to scripture, and also that they don't know the power of God.
These two things will keep us from many similar errors: knowing the scripture and the power of God.
Mark 12:24King James Version
And Jesus answering said unto them, Do ye not therefore err, because ye know not the scriptures, neither the power of God?