How much would you risk for a stranger?

I realized that for a stranger I would not risk my live or anything of mine.Which that leads to if the stranger needs help then i'll probably risk something for that person. At the end you never know if he will hurt you or kill you, so might as well not try risking for a stranger!In the book THE FIGHTING GROUND, Jonathan{main character} helps this little boy he finds. Then goes off into the forest at night to save his and the little boy's life. He risked gettin cought or his life. Thats why i think you shouldn't really help a stranger or risk anything for him unless you have a reason!