That's why Priscilla and I started the Chan Zuckerberg Initiative and committed our wealth to promoting equal opportunity. These are the values of our generation. It was never a question of if we were going to do this. The only question was when.

Millennials are already one of the most charitable generations in history. In one year, three of four US millennials made a donation and seven out of ten raised money for charity.

But it's not just about money. You can also give time. I promise you, if you take an hour or two a week -- that's all it takes to give someone a hand, to help them reach their potential.

Maybe you think that's too much time. I used to. When Priscilla graduated from Harvard she became a teacher, and before she'd do education work with me, she told me I needed to teach a class. I complained: "Well, I'm kind of busy. I'm running this company." But she insisted, so I taught a middle school program on entrepreneurship at the local Boys and Girls Club.

I taught them lessons on product development and marketing, and they taught me what it's like feeling targeted for your race and having a family member in prison. I shared stories from my time in school, and they shared their hope of one day going to college too. For five years now, I’ve been having dinner with those kids every month. One of them threw me and Priscilla our first baby shower. And next year they’re going to college. Every one of them. First in their families.

We can all make time to give someone a hand. Let's give everyone the freedom to pursue their purpose -- not only because it's the right thing to do, but because when more people can turn their dreams into something great, we're all better for it.

Purpose doesn't only come from work. The third way we can create a sense of purpose for everyone is by building community. And when our generation says "everyone", we mean everyone in the world.

Quick show of hands: how many of you are from another country? Now, how many of you are friends with one of these folks? Now we're talking. We have grown up connected.

In a survey asking millennials around the world what defines our identity, the most popular answer wasn't nationality, religion or ethnicity, it was "citizen of the world". That's a big deal.

Every generation expands the circle of people we consider "one of us". For us, it now encompasses the entire world.

We understand the great arc of human history bends towards people coming together in ever greater numbers -- from tribes to cities to nations -- to achieve things we couldn't on our own.

We get that our greatest opportunities are now global -- we can be the generation that ends poverty, that ends disease. We get that our greatest challenges need global responses too -- no country can fight climate change alone or prevent pandemics. Progress now requires coming together not just as cities or nations, but also as a global community.

But we live in an unstable time. There are people left behind by globalization across the world. It's hard to care about people in other places if we don’t feel good about our lives here at home. There’s pressure to turn inwards.

This is the struggle of our time. The forces of freedom, openness and global community against the forces of authoritarianism, isolationism and nationalism. Forces for the flow of knowledge, trade and immigration against those who would slow them down. This is not a battle of nations, it's a battle of ideas. There are people in every country for global connection and good people against it.

This isn't going to be decided at the UN either. It's going to happen at the local level, when enough of us feel a sense of purpose and stability in our own lives that we can open up and start caring about everyone. The best way to do that is to start building local communities right now.

We all get meaning from our communities. Whether our communities are houses or sports teams, churches or music groups, they give us that sense we are part of something bigger, that we are not alone; they give us the strength to expand our horizons.

That's why it's so striking that for decades, membership in all kinds of groups has declined as much as one-quarter. That's a lot of people who now need to find purpose somewhere else.

But I know we can rebuild our communities and start new ones because many of you already are.

I met Agnes Igoye, who's graduating today. Where are you, Agnes? She spent her childhood navigating conflict zones in Uganda, and now she trains thousands of law enforcement officers to keep communities safe.

I met Kayla Oakley and Niha Jain, graduating today, too. Stand up. Kayla and Niha started a non-profit that connects people suffering from illnesses with people in their communities willing to help.