how volunteering helps to build more cohesive communities?

I think it empowers people to be part of the solution. People volunteering are actively helping there society. They aren't sitting back and complaining. They are contributing. They are building a better society.

Plus rich can work along side the poor, Black along side White, Jews among Christians. The people in need of help will get a sense that society cares and that people care and will go out of their way to help out. It shows that society actually benefits them and works for their good. By volunteering, people are empowered to work within their own communities to solve problems and make conditions better.

I also found this:

Why should governments be interested in promoting volunteering? Especially when some voluntary activity can be seen as a challenge to the authority of the state. There are two major benefits of volunteering. First, an economic one: volunteering makes an important economic contribution to society. Activities undertaken by volunteers would otherwise have to be funded by the state or by private capital. Volunteering adds to the overall economic output of a country and reduces the burden on government spending. But volunteering has a second and perhaps more important benefit. Volunteering helps in the building of strong and cohesive communities. It fosters trust between citizens and helps develop norms of solidarity and reciprocity which are essential to stable communities. Moreover, by helping to build this 'social capital' volunteering also plays a role in economic regeneration.