Wearing a seat belt can save your life, which is the most important reason to always have the safety belt buckled around you. However, there are plenty of other reasons to wear this protection, too.
Seat belts can aid in preventing you from hitting the windshield, being thrown from the vehicle, banging around the vehicle and hitting the steering wheel, door, etc. Seat belts are known to offer the best defense against road hazards; aggressive, impaired, or distracted drivers.
Women who are pregnant are more protected when they're wearing a seat belt.
More information on seat belts: