Jesus is called the firstborn overall creation not because he was the first to be created, but because he is the source of creation. He brought into existence what did not exist before. From nothing, our Lord created everything.
Everything was made through him and “without him nothing was made” (John 1:3). “In him all things were created… visible and invisible”. He is the creator and sustainer of the universe. “In him all things hold together” – Adapted.