From Sahih Bukhari (Hadith 6921):
Narrated Ibn Mas`ud:A man said, "O Allah's Messenger (ﷺ)! Shall we be punished for what we did in the pre-Islamic Period of ignorance?" The Prophet (ﷺ) said, "Whoever does good in Islam will not be punished for what he did in the Pre-Islamic Period of ignorance and whoever does evil in Islam will be punished for his former and later (bad deeds)
Reference: Bukhari 6921