Colossians 1:16

For by him all things were created, in heaven and on earth, visible and invisible, whether thrones or dominions or rulers or authorities—all things were created through him and for him.

-Colossians 1:16

So, what does it mean for Jesus to be "the image of the invisible God" and for him to be "the firstborn of all creation"?  It means that all things were created by him, through him and for him.  Paul even goes on to start listing some categories that fall within "all things".  Just in case you thought "all things" was limited to earth or heaven, he lists both.  "All things" also includes things you can see and things you can't see.  I don't know if it would've been helpful for Paul to be more specific about what he meant by "all things", because he helps to describe that "all things" really does mean all things.  Now I understand that some will say that it's implied that Jesus himself is excluded from the definition of "all things" by way to mean that Jesus was created before "all things" were created.  I don't think that Jesus was created and I do believe that Jesus is God.  By him and through him and for him were all things created.  This little verse is a small window into helping us understand what Paul meant by saying that he is the "image of the invisible God" and that he is "the firstborn of all creation".  Part of that means that he created everything.  I don't think it means that he was the first created being, which some may think "the firstborn of all creation" means.  I don't see how saying that Jesus was the first created thing is supported by the fact that Jesus created everything (or everything else, if that's the case).