Is your assumption that it is true that we are here to help others, then may I ask what you base your assumption on, or are you echoing the widely held views of others?
In other words, do you have your own personal religion or philosophy that woul demand that you help others, or is it instinctual?
What I don't get is this - if, as some people assert, we all have a guardian angel looking out for us, then how come people die, have terrible accidents, develop cancer and so on? What are their angels doing at the time?