When that threat goes away, less people will find a draw in religion. But religion is a fundamental element of our civilization - it ties us together in communities, it encourages altruistic behavior. If religion is greatly weakened, then our civilization will be weakened also. Body Control Biotechnology reaches the point where we can rebuild people's bodies at will. Facial features, body size, fingerprints, retina patterns, all can be changed.
Identification based on physical features is no longer possible.
We're probably hardwired to respond to the physical appearance of people. Height and size. We might be able to require some sort of built in identification, but criminal organizations and foreign governments would attempt to circumvent such approaches. We'll be able to change their innate intelligence, their capacity for various mental tasks - and more importantly their innate emotions and motivations. Totalitarian countries fail because their systems inherently fail to provide the motivation needed to make their subjects effective and efficient.