Afaik Vinaya also has few things to say on living with lay people.
SarathW wrote:I see lot of homeless people in the street.
I feel helpless as I can't help all of them.
I see where you are coming from and this comes up for me as well. I tend to help those who are close to me and appreciate the opportunity to practise giving in general, however i cant help everybody and i feel bad when i dont share all i have, including requisites and when i spend money on stuff i dont need like extra good food ie. Also if we feel bad about not helping people in front of us, not helping poor people far away is no diffrent, there is no justification for not living at absolute minimum and donating rest of one's resources to others be it monastics or the poor of the world.
The only comperhensive solution i know of is giving up money and becoming a renunciate, helping the world by giving Dhamma to people.