1. It's a good thing that when God created the rainbow he didn't consult a decorator or he would still be picking colors. Sam Levenson 

2. I decide it's a good thing that I don't see Sean try to capture Ian's incandescent dance.

3. It's a good thing that I wasn't there.

4. Perhaps it's a good thing that Dizzy retired.

5. It's a good thing that New Year's was a holiday because everyone had a hangover.

6. It's a good thing that you have finished with that worthless young man.

7. It's a good thing that other countries are becoming spacefaring nations. No fear of any one nation dominating space as private companies are getting into the race as well.