Rest in power

Rest in power is a saying that is used to replace "rest in peace," which is said after someone dies. The phrase "rest in power" is used for people who have dedicated their lives to activism or those who have died due to oppression, such as racism, homophobia, transphobia, etc. Using the term "rest in power" instead of "rest in peace" sends a message that the dead person cannot rest in peace until change occurs. "Rest in power" also means that the dead person is making changes in society despite being dead.
The phrase "rest in power" is used in progressive groups.
History.
"Rest in power" is quite new. It first appeared in 2000 in honor of a graffiti artist in Oakland, California who was shot and killed. Later, it began to be used for people who were killed in shootings or murdered.
Black Lives Matter.
People who are part of Black Lives Matter use "Rest in power" to remember all Black people who died because of racism. Even though the phrase wasn't used yet during the Civil Rights movement of the 1950s and 60s, people still say "rest in power" when talking about people who died because of racism back then or were involved in the movement. For example, Emmett Till died in 1955, but people still say "rest in power" when they're talking about him.
When Trayvon Martin died, his parents used the phrase to honor him. They wrote a book called "Rest in Power" about his life.
Transphobia.
An American trans girl named Leelah Alcorn killed herself in 2014 because she could not deal with her parents' transphobia. Even after she died, her parents still didn't treat her right and they called her by her deadname (name used before transitioning) instead of the name she wanted to be called. People used "rest in power" to honor Ms. Alcorn and recognize the fact that she wasn't treated right as a transgender person, even after she died.