There is no greater thing that can be done in this life, other than working for God. You will receive satisfaction in this life for work welldone, and rewards in the next life.
As for someone you can invest in, they are all around you, the single mom who is struggling, the dad that is not allowed to see his children, the grandparent who is alone, the children whose parents work all the time, the man who is homeless, the alcoholic, the drug addict, on and on and on this goes, but I think you catch my drift.