Cephas was born and raised in West Philadelphia and is a graduate of Central High School from the class of 2002.

[2][1] Cephas previously served as the Deputy Chief of Staff to Philadelphia City Councilman Curtis Jones, Jr. before running for the state legislature.

[2] Cephas was first elected to the Pennsylvania House of Representatives in 2016 after defeating incumbent Rep. Lynwood Savage in the Democratic primary.

[3] Running unopposed, Cephas was re-elected to a second term in the House in the 2018 general election on November 6, 2018.

[4] Cephas was appointed as deputy whip of the Pennsylvania House of Representatives for the 2021–2022 session and to PennVEST in 2021.