Diving courses give you the knowledge, competency and confidence to begin or continue your diving adventures.
The education and understanding which you gain by doing a certification gives you confidence which makes you a responsible diver. This means that you are a valuable dive buddy and can handle an emergency situation if one arises, calmly and professionally.
When I first dove I thought the concept of breathing underwater would be fun, I quickly found out that there is a lot of great experiences to be had, but that a lot of things can also go wrong when you are under the water. I also learnt a great deal more about how your body reacts to diving and this reinforces to me the importance of proper certified diving courses and the value that they add to your fantastic adventure sport of scuba diving.
The PADI dive structure in summary.
Step 1 - Open Water Dive Certification
Step 2 - Specialty Dive Course
Step 3 - Master Scuba Diver
With plenty of other education along the way.