Silsilat al-Ahadith al-Sahihah

Sayyiduna Anas bin Malik (may Allah be pleased with him) narrates that the Messenger of Allah (peace and blessings be upon him) said: "Do not be hasty in judging someone as good or bad by looking at his deeds; rather, see upon which deed his life ends, because (the reality is that) a person performs righteous deeds for a period of time, and if death comes to him while he is upon those deeds, he will be among the people of Paradise. But his state changes and he begins to do evil deeds (and death comes to him upon those). Similarly, a person performs evil deeds for a period of time, and if death comes to him while he is upon those deeds, he will enter the Fire. But it happens that his state changes and he begins to do righteous deeds (and death comes to him upon those). When Allah Almighty intends good for a servant, He grants him the ability to do righteous deeds before death, then seizes his soul."