Eight words thunder in our souls: Without you, we can't; without us, you won't. You have chosen to do your work through your people. --Lloyd John Ogilvie from "For They Shall Be Fed"
Without God, we can't experience the life we were created to live. Without God, our motivation to help the needy becomes self-serving rather than God serving.
Without us, God won't. I've had to think about this for a while. One thing I have learned from being involved with recovery ministry is that God uses people to make a difference in other people's lives. God puts people in our lives at specific times for specific purposes. I am awe-struck when I realize that He has used me to touch the life of another. Amazing that He uses me for His purposes. I am absolutely humbled by that.
God also does this in big ways, which is really what the quote above is referencing. In times of disaster or need, God's people and God's church have stepped in to fill a need and to help in a crisis. The church is often able to help in ways that government programs and individuals can't. When God's people come together to do something with God and for God, mountains get moved, red tape gets cut, and action is taken.
God doesn't exactly need us but isn't it wonderful that He has chosen to use us anyway!