When Jesus asked this question two thousand years ago, He was alerting His followers about the prevailing spiritual condition of people on earth at the time of His return. Jesus knew the answer: the close of the age would be marked by a mass defection from the truth.
The Coming Apostasy
Satan is using spiritual mass deception to fool the world, even many professing Christians. The cost of spiritual deception is far greater than being conned by counterfeit currency because it has eternal implications.