Many folks feel they must have a credit card, mainly because of their ability to have an advance on their money. This when out of control, can lead to a financial mess if you can't manage the money well.
If you are able to pay off your credit charges each month, then you are very responsible financially. Monthly payoffs gives you an excellent credit rating, which would come in handy in the future when you want to buy a car or a home for instance.
On the other hand though, if you are not good at managing your money then the credit card is going to be your worst enemy. By letting the balance pile up month after month you reach a point where you can't pay off the balance, and then your in trouble with the bank. (Unfortunately some North American governments think that they can do this with impunity). But that is a different story.
Use your card sparingly, pay the balance each month and don't rely too heavily on it.