‘Umar bin al-Khattaab (may Allah be pleased with him) said:

من قال: انه عالم فهو جاهل, و من قال: انه مؤمن فهو كافر, و من قال: انه في الجنة فهو في النار

“Whoever says he is an alim (learned person) then he is ignorant, and

whoever says he is a believer then he is a kaafir, and

whoever says he is in paradise then he is in the fire.”

Source: Ibn Rajab’s “Fadl ilm Salaf ala ilm Khalaf” under the chapter “Signs of knowledge that does not benefit”