In conducting his experiments, Victor Frankenstein is motivated by the desire for knowledge and power. In relation to the former, he wants to push back the frontiers of scientific knowledge, to show the world how it's possible to create a living creature from the body parts of dead humans.
As regards the desire for power, Frankenstein wants to create a race of creatures who will populate the earth, who will bow down before him like a god and worship him as their creator. Most scientists are motivated in their research and in their experiments by a genuine desire to improve people's lives. But for Victor, it's all a gigantic ego trip. He's not creating the Monster for the benefit of humanity; he's doing it for himself, for his own gratification and self-aggrandizement.
The consequences of Frankenstein's overwhelming desire for knowledge and power are catastrophic, not just for humanity as a whole but for Victor himself. In creating the Monster, he unwittingly endangers himself, those around him, and society as a whole.
Once the Monster has been unleashed upon society, it starts to take on a life of its own. As it does so, it breaks free of the control of its creator, making it impossible for Frankenstein to rein in the hideous creature that he created. This may not have been intentional on Victor's part, but it's the direct consequence of his insatiable appetite for knowledge and power.