Abu Hurairah (May Allah be pleased with him) reported:
Messenger of Allah (ﷺ) said, "If a believer had full knowledge of the chastisement of Allah, none would covet His Jannah; and were an infidel to know the Mercy Allah has, none would despair of His Jannah".[Muslim]. (DE)
Arabic/English book reference (DE): Book 1, Hadith 443 (DE)