Rest days are equally important as training days. In order for your muscles to grow and get stronger, they need time to recover. Without adequate rest, you may find your body doesn't respond to training stresses the way you want it to.
Hard training every single day can be rough on your body, your mind, and your lifestyle. Use rest days to help you maintain healthy habits and a healthy body.
If you feel you need to lose some extra body fat, or just need to move a little bit, then go do some light cardio. Take a walk with your family, or go for a short bike ride. Don't do anything too strenuous, though. The point of the next couple days is recovery.
It's also a great idea to use the weekends to prepare your meals for the upcoming week. Nutrition is often the number one killer of fitness goals. If your meals are already prepared and in the fridge, you're less likely to eat something that won't help you reach your goals.