Overall Topic: Adopting a pet
Main Idea: Adopting a pet from a shelter or rescue provides significant benefits not only for the animal but also for the community and potential pet owners.
Point #1: Adopting shelter pets can help save the animal's life.
Point #2: Adoption helps control pet overpopulation.
Point #3: Adopting a pet usually costs less than buying one from a pet store or a breeder.
Combine the main idea and points 1, 2, & 3 to create a thesis statement:
Adopting a pet from a shelter or rescue not only saves a life and helps in the fight against pet overpopulation, but it also provides a more affordable option for pet ownership.