If you are single and have no dependents, then you do not need life insurance. However, if you have dependents, then you need life insurance. The obvious question is how much life insurance a person needs. In the event of your death, then your dependents will need enough money for immediate expenses and future expenses. Remember that life insurance benefits are not taxable under federal income tax, but life insurance proceeds may be taxed under estate tax law.
Immediate expenses are funeral expenses, probate costs, and estate taxes.
Future expenses are all expenses which your dependents will incur over time, to include food, housing, education, etc. Determining future expenses varies based on whether you have a mortgage, if you spouse works, if you have small children, etc. Your life insurance agent should help you determine what level of benefits you require. You pay premiums, and in exchange, the policy pays a sum of money to your beneficiaries if you die while you are covered. There is no savings or investment component.