Jesus goes beneath their puzzle to the root of their mistake. They did not need a cleverer argument; they needed to know two things: the Scriptures and the power of God. Gill notes that what Matthew gives as a statement, "Ye do err" (Matthew 22:29), Mark gives as a question, "which, with the Jews, was a more vehement way of affirming." Matthew Henry paraphrases the force of it: "Ye cannot but be sensible of it yourselves." The question invites the Sadducees to see their own error rather than simply be told about it.

Jesus answers His own question by addressing both causes. On the power of God: the risen "neither marry, nor are given in marriage; but are as the angels which are in heaven" (Mark 12:25). On the Scriptures: "have ye not read in the book of Moses, how in the bush God spake unto him, saying, I am the God of Abraham, and the God of Isaac, and the God of Jacob?" (Mark 12:26). He concludes, "He is not the God of the dead, but the God of the living: ye therefore do greatly err" (Mark 12:27). The Sadducees make no reply in Mark's account, and soon after, "no man after that durst ask him any question" (Mark 12:34).

"Err" translates planasthe, from planao. Thayer's lexicon gives its passive sense as "to go astray, wander," and figuratively being led into error. The tense is present: they are going astray right now.

Barnes says "The 'Scriptures,' here, mean the books of the Old Testament." He notes that other Old Testament passages state the resurrection more plainly (Daniel 12:2; Isaiah 26:19), but because the Sadducees had appealed to Moses (Mark 12:19), Jesus "wished to meet them on their own ground" and answered from Moses too (Exodus 3:6). As for God's power, Barnes says, "They probably denied, as many have done since, that God could gather the scattered dust of the dead and remould it into a body."

Jesus' question shows that right belief about God rests on two things held together: what God has said and what God can do. The Sadducees knew the words of Moses, but missed what those words revealed about the living God. They pictured the resurrection, then rejected it, because their picture of God's power was too small.

The answer Jesus gives is about God's faithfulness. At the bush, long after Abraham, Isaac, and Jacob had died, God still called Himself their God (Exodus 3:6). Barnes reasons that they must therefore still be living somewhere, "for God is not the God of the dead," and notes that this was the very point "the Sadducees denied" (Acts 23:8). God does not lose those who belong to Him.