Until today “mistakenism” was not a Word. This changes everything! Jesus always had just the right thing to say. Think about it. The words He spoke were very pointed, useful and “with authority” to the people of His day. Still, the skillfulness with which He crafted His words brings them swinging like a powerful punch right in to the 21st Century where they are as useful and straightforward as they were the day He spoke them.
In dealing with the religious legalism of the day, a fatal malady that ends the witness of more churches today than anything else I can list, Jesus spoke these words in Mark 12: 24:
24Jesus answered and said to them, “Are you not therefore mistaken, because you do not know the Scriptures nor the power of God?
I like how The Message, a modern day paraphrase puts it:
24Jesus said, “You’re way off base, and here’s why: One, you don’t know your Bibles; two, you don’t know how God works
Jesus’ bottom line teaching is that we are often mistaken. There is no question about it. "If you think you ain't, you is"! The interesting part of the teaching is that being mistaken is the symptom but Jesus also identified the disease. We become mistaken when we do not know the Word of God. I am reminded of some other words of Jesus, “Man shall not live by bread alone, but by every word that shall proceed from the mouth of God”. The apostle Paul fleshed that out by saying, “Faith comes by hearing, and hearing by the Word of God.” If you are not pursuing the knowledge of His Word, you are setting yourself up for a lifetime of knowing less of Him that He desires. You are being content with dirty water from the puddle when He wants you to drink freely from the fresh, cool spring of His written wellspring.
There are two streams of thought on the last part of this verse. One is that we also don’t know the power of God. Perhaps we should be seeking the power of God in the same way as we are to be seeking the Word of God. That would mean that we need to be seeking the Lord and yielding our lives to Him. The other interpretation I like better, we don’t have the power of God because we do not know His Word. It seems we often suffer from the listlessness of an unfruitful life when God would have us slicing through the deep waters, both calm and storm tossed, to boldly reach the destination of His will.