Musnad Abu Ya'la al-Mawsili 152:63

Abu Khaythama narrated to us, Jarir narrated to us, from Mansur, from Abu Wa'il, from Abdullah, who said: Some people said to the Messenger of Allah (may Allah bless him and grant him peace), "Shall we be held accountable for what we did during the Pre-Islamic Period (Jahiliyyah)?" He said, "As for whoever among you does good in Islam, he shall not be held accountable for it. And whoever does evil, he shall be held accountable for his deeds in the Pre-Islamic Period and in Islam."