Think, "Lord Of The Flies".....
Bunch of choir boys stranded on an island. No adult authority, just the boys own decisions. How does the book end...........utter anarchy.
Ok, it was non-fiction, but it certainly isn't an unreasonable possibility. Just raise some of your own from babies to adulthood..........From helplessness to accountability..............Before accountability, they need discipline to learn to be sensitive to others, to share, to just plain obey and do what's good for them and others around them. Then gradually there's a dawning.......At least hopefully they aren't born with a seared conscience, and the start to apply the principles that you've taught them.
Now as far as teaching them a wide spectrum of belief systems or religions or philosophys.........I would think that parents would naturally desire, to teach the ethics and morals that they themselves adhere too, and most likely the base or foundational belief system that spawned those ethics or morals. When a child reaches the ages of accountability, they will have the opportunity to go into the world and also test out other religious beliefs/philosophys against their childhood training and decide for themselves.
Many folks end up joining other religions or refraining from the religions of their parents. This is the maturing part of becoming a full fledged human being. Many will reject Mom and Pop's belief system, and will years later return to it.
It's a natural and healthy part of maturing humanity in it's early adult stage to "test" the waters so-to-speak, and see whats out there.
Our kids can't be guarded in guilded cages. I know it's scarey as parents, but if we want them to maturate and return to us as full fledged adults with full fledged powers of analysis and reason, we must let go.
In their early ages, we apply our religious beliefs as that's how we as parents perceive our reality the world and truth. It doesn't sentence our children to a life of never having a choice. We hope to foundationally give them a kick-start, and then pray for them and hopefully are availbable to give counsel at times if asked. Even then, when they are at that accountability time of life, we must be careful to not harrangue them with our belief system, unless they ask us specifically about how it in light of needed counsel. Never the less, respect their adulthood, and they will in-turn respect you more and the foundational principles that you passed on to them in childhood.
Maybe some of us are on the right track and some of parents aren't. There will be a time when we will all be accountable for what we passed onto our offspring. I guarantee it.