Like other human beings, Jesus knew intuitively that A is A. Every rational thought and expression he made implied this law (principle of identity). He stated the principle of identity clearly when he said, “But let your ‘Yes’ be ‘Yes,’ and your ‘No’ ‘No'” (Matt. 5:37). He knew that without this principle we could not even think or talk coherently. For were the principle of identity not true, then God could mean not God, believe could mean not believe, and good could mean not good.
— Norman Geisler, from The Apologetics of Jesus, p. 69