There are days when it feels like the world really is going to shit. And when that happens, we need to remember that there's actually a lot of hope for the future.

As one dad recently expressed in an 'open letter' to his second-grader daughter, there's a bright generation growing up right now, and they will be the "smartest, most adaptable to change" people that have lived so far.

"Many adults will call your generation lazy, and will verbally ponder whether it will doom the planet. But they are wrong," writes Stephan Neidenbach, a middle school teacher from Maryland, US.

"The entire world can be fed and cared for, and the only thing standing in the way is politics. Innovation by those born in the 21st century will one day even remove that last barrier."

It's a grand statement, but at its heart is an inspiring sentiment that's been expressed before, most famously in a quote Neidenbach shares from the late astronomer and science communicator Carl Sagan.

"Advances in medicine and agriculture have saved vastly more lives than have been lost in all the wars in history," Sagan wrote in his 1995 book The Demon-Haunted World: Science as a Candle in the Dark.

Neidenbach goes on to reference scientific skepticism, the special brand of critical-thinking-inspired approach to life that was embodied by Sagan during his lifetime.

"Your father considers himself to be a critical thinker. The same social media that has given a new voice to hate speech and paranoia over innovation has also given a voice to others like himself," he writes.

Neidenbach himself has first-hand experience in banding together like-minded people online. He's the founder of a Facebook page titled We Love GMOs and Vaccines, which currently has nearly 130,000 likes.

The page is exactly what is says on the tin, with content liked and shared by people who have a strong distaste for pseudoscience, especially when it comes to the two topics in the page title.

Last year the page was briefly taken down by Facebook after anti-vaccine campaigners repeatedly reported it as 'abuse', tripping the social network's algorithm.

But despite such run-ins with 'the opposition' online, Neidenbach also writes that we shouldn't just surround ourselves in an ideological bubble.

"Samantha, I hope you will learn many lessons from me. I will give you all the tools you need to become a critical thinker yourself," he addresses his daughter.

"I hope you will join me in not fearing scientific gifts like vaccines or new seed breeding techniques. But be wary of 'the group'. Have friends, but be sure to have friends that also disagree with you.

"Surrounding yourself with people who see the world the same way is not being a critical thinker."

We love this advice. And not just for a little girl in second grade.

You can read the whole letter on Neidenbach's Medium page here.