Mark Zuckerberg wants Facebook groups to play an important role that community groups like churches and Little League teams used to perform: Bringing communities together.

And with nearly 2 billion people around the world on Facebook today, he might have a chance to make it happen.

Zuckerberg laid out his lofty ambition in a Chicago speech last week that suggested Americans are in need of something to unify their lives.

"It's so striking that for decades, membership in all kinds of groups has declined as much as one-quarter," he said during a rally for Facebook users who've built large community-support groups on the site. "That's a lot of of people who now need to find a sense of purpose and support somewhere else."

He added, "People who go to church are more likely to volunteer and give to charity — not just because they're religious, but because they're part of a community."

Zuckerberg thinks Facebook can help, using its networking power to organize people.

"A church doesn't just come together. It has a pastor who cares for the well-being of their congregation, makes sure they have food and shelter. A little league team has a coach who motivates the kids and helps them hit better. Leaders set the culture, inspire us, give us a safety net, and look out for us."

Zuckerberg has now had six months to study how some savvy Facebook users, reportedly including Russian hackers, turned the internet platform he built into an online machine that spread fake news and helped elect Donald Trump as President -- whom he snubbed this week.

Now that he's seen how powerful a tool Facebook can be for spreading disinformation, Zuckerberg is pushing to use Facebook's artificial intelligence algorithm to make the site even better at organizing online communities.

"We started a project to see if we could get better at suggesting groups that will be meaningful to you. We started building artificial intelligence to do this. And it works. In the first 6 months, we helped 50% more people join meaningful communities."

His ultimate goal is to convince 1 billion users to join Facebook communities.

"If we can do this, it will not only turn around the whole decline in community membership we've seen for decades, it will start to strengthen our social fabric and bring the world closer together."

Bringing people closer together is so important that "we're going to change Facebook's whole mission to take this on," Zuckerberg said in Chicago.