In a statement on Saturday, he said those who claim to be flag-bearers of Islam but perpetrate massacres in the name of Islam know nothing about the religion.
He said such radical groups misinterpret the Quran in order to reach their objectives.
Gomaa further condemned a recent suicide attack by extremist groups against an academic center in Egypt and described it as an example of lack of reason and insight in extremist groups.
He said even if someone has committed murder his case should be considered by the judiciary and that it is not acceptable for everyone to take the law into their own hands.