"Teacher, we know that you speak and teach correctly, and ... teach the way of God in truth" (v21). The spies sent by the priests tried to trap Jesus into some anti-government, radical statement. Jesus turned their deceitful questions around and spoke to their hearts: "Render to Caesar the things that are Caesar's, and to God the things that are God's" (v25). He answered their questions about the resurrection in the same way. Verbal games were nothing to Jesus; truth was everything.
We can't pretend with Jesus. He is Truth, and He knows our hearts better than we know ourselves.