“There comes a time when silence is betrayal.” These words spoken by Dr. Martin Luther King Jr. have inspired many—most recently and prominently, tennis superstar Serena Williams. Williams used Dr. King’s quote in a Facebook post she wrote on Sept. 27, when she became one of many accomplished athletes in recent news to speak up about racial injustices in the United States. The Facebook post discussed her own personal fears and experiences with racial prejudice, ending with a powerful statement signed off by the tennis player herself: “I Won’t Be Silent.”

Williams, who is currently ranked second in the world, holds the fourth highest number of major titles at 38. Over the course of her career, Williams was ranked number one for 309 weeks. Her athletic excellence is incredible and it has truly given her a platform on which she has now chosen to spread this powerful message.

When NFL player Colin Kaepernick started kneeling during the national anthem to raise awareness and bring attention to a movement of racial equality, it drew attention across the country. His movement has spread, with many athletes and fans alike showing signs of solidarity through kneeling, sitting, raised fists, or other symbolic gestures, specifically during the national anthem.

This has received significant backlash; while many athletes have joined his movement, other big names in the sports world, such as former NFL coach Mike Ditka, have vocalized their disapproval, with Ditka even quoted saying he has “no respect” for Kaepernick. Williams’ Facebook post is the most recent in this string of solidarity displays, and serves as a call to action when she pleads people not to stay silent.

Williams’ post contains a highly reflective section, where she questions what she herself is doing to cause change. This introspection on her part is inspiring for all, and can serve as an impetus for change as we are called to look inwards and ask what we are doing to fix such pressing issues.

The media has covered these silent protests and their spread quite extensively. Regardless of which side of the debate you may stand on, these athletes are using their spotlights to call light to issues they feel passionately about, working to potentially spur a positive change in the country. As Williams eloquently states in her post, “I realized we must stride on—for it’s not how far we have come but how much further still we have to go.”