I just hope it's not a growing through pain experience.
A danger with a lot of these idealogical groups is the classic cult/abusive behavior of "love bombing", which can be especially effective with younger people trying to figure out themselves and where they "fit" in the world. Add all that to the lack of life experience causing that sort of behavior to not ring alarm bells and it's a potent recipe for learning things the hard way when it all comes crashing down.
Sidenote: Even if this was a kid publicly declaring healthy beliefs, I really don't get why the response isn't "Ok, cool. Moving on..."
This sort of "championing" of impressionable youths by strangers, in response to the youth simply saying they believe a certain thing, just gives me the skeevies. Doesn't feel genuine to me.
Probably not as 14-18 is when you are most susceptible to beliefs. The brain is developing still and as it locks in the stuff around it. It becomes your core belief system.
I've yet to meet an older person who has not been able to change their opinion. In fact I reckon the belief that you can't change is a very, very dangerous one.
Broadly speaking, as you get older, you tend to become more rigid in your core beliefs. But not always. And not in everything. It doesn't mean you can't change, but people become less likely to change. As you get older, you have more inertia to overcome, and more years of sunk-costs.
Your core values are unlikely to change though. It isn't impossible but when you are a young adult everything is new and you are basically a sponge. What happens when you are young profoundly influences who you become.
my 14 year old self would view my current self with horror, recoil and run away without giving current self a chance to explain the lifetime of choices, learning, and impossible decisions that got me here. I guess what I'm trying to say is, like most 14 year olds I was an idiot (a special kind of idiot, but an idiot nonetheless). we are polar opposites.