It's Jesus' desire for His church
God speaks of the blessings that come when His people are together. It is in the context of unity that He sends His presence and His provision. In what is regarded as one of Jesus' most significant prayers, He prayed that His church would be together as one. He promised that He would be present when together with us when two or more gather together. The very first church, when the church was arguably in its purest form, was so dynamic because it was together in one accord. Jesus longs that His church be together.
It describes the church's role in the community.
I am convinced that the only way to change the world is by working together. There is no one agency vibrant or big enough to do it alone. It is the expressed role of our church to partner together with schools, government, citizens, community groups, other churches, and non-profits to work together to make the world a better place. We are to be a life-giving hub in our city's eco system. We make lives and cities healthier by partnering together with them.