The purpose of life insurance is simple: to make sure that your kids - or other people who depend on you for financial support - will be OK if you die prematurely.
Contrary to what all too many insurance agents will tell you, you almost certainly don't need to have life insurance for your entire life. You need it most when you're a young adult with young kids, when you have yet to build up assets that your family can fall back on if something happens to you. If you die while your children are still in diapers, where's the money going to come from to raise and educate them? Right: life insurance. Once they're grown up, you no longer need it.