To deliver vast new resources to humanity, we must pioneer and occupy the moon, Mars, and perhaps even beyond.
Terraforming our moon will take many decades and vast abilities. Before we can begin, we'll have to master the resources of our solar system - especially transporting raw masses over interplanetary distances.
The moon's closeness is a huge advantage: To make it habitable, we would first have to bombard it with water-ice comets, a tricky endeavor best attempted with the many resources waiting on and near Earth.