Aqeedah of the Salaf: The Outcome of the Slaves is Unknown – Abu Muhamamd al Maghribee [Audio|En]
The People of Hadeeth believe and testify that the end of the slave is unknown. No one knows what his end shall be. They (People of Hadeeth) do not pass judgement on a specific person that he will be from the people of Paradise or from the people of Hell, because that is something which is hidden from them. They do not know in which state a person will die, whether it is upon Islaam or unbelief, so due to this fact they say:
“Indeed we are Believers, if Allaah wills.”
That is, from those Believers who will have a good end, if Allaah wills 
 The Prophet(صلى الله عليه وسلم), said:
Do not be delighted by the actions of anyone until you see how he ends up”.
Related by Ahmad [ 3:120,223 ] and lbn Abee ‘Aasim [ 393-395 ]. The isnaad is Saheeh.
The Explanation of the Creed of the Salaf, by Imaam Abee Uthmaan Ismaa’eel bin Abdir-Rahmaan As-Saaboonee,rahimahullaah, as explained by our noble sheikh al-Allaamah Rabee’ bin Haadee Al-Madkhalee, hafidhahullaah.