Question

service to others is a form of sacrifice

Answer 1

Yes you are right . But others should remember that they should repay them and should not disrespect their service.

Answer 2

service to other includes many things.
1. love
2. compassion
3. care
4. compassion

service to mankind is the ultimate service to the all mighty father (god).

our selfless action can create a new hope for the society.