Hmmmm... if I remember correctly from my course in logic and scientific method, this is called "begging the question." I could be wrong - it's been about 40 years since I took the course.
Of course, any human being can be indoctrinated, but if we teach our children well, and teach them critical thinking skills they should be able to distinguish between truth and fiction when they are more mature and able to think for themselves.
Some of the things I was indoctrinated (aka "brainwashed") in as a young nursing student I hold true to this day - being responsible, being on time, aseptic technique, professional demeanor, including dress, and some general principles of patient care, including how to interact therapeutically with people.
There are other things I was taught as a child that I no longer believe - for example, that it's ok to go to church so long as you really don't believe all that stuff and make it a way of life.
There is a vast difference between "religion" (which for me as a born again believer these days is clicker training - not related to what most people would think of when they think of "religion") and faith.
Adults, parents in particular have an obligation and a duty to teach their children the best they know. If they teach what they think is the best and teach their children how to think, I believe they have done their job, even if the best they know really isn't the best.
Children need guidance, just like dogs. Excuse the analogy, but I am a professional dog trainer these days and to me it is obvious - lots of bad dog-rearing, lots of bad child-rearing. An untrained child is analogous to an untrained dog. Both are exceedingly obnoxious and disruptive to society.
We cannot legislate the way people train their children, outside of outright abuse. Parents have a right - and should have a right - to teach their children what they believe to be true. We can only hope that they teach them well.