Mark 12:27

"He is not the God of the dead, but the God of the living: ye therefore do greatly err."

Cross References (ranked by relevance)

For to this end Christ both died, and rose, and revived, that he might be Lord both of the dead and living.

(As it is written, I have made thee a father of many nations,) before him whom he believed, even God, who quickeneth the dead, and calleth those things which be not as though they were.

Mark 12:24

And Jesus answering said unto them, Do ye not therefore err, because ye know not the scriptures, neither the power of God?

Hebrews 3:10

Wherefore I was grieved with that generation, and said, They do alway err in their heart; and they have not known my ways.