Allah owes you nothing in this life. Your presence in this life does not entitle you to ANY rights. Therefore, even if Allah were to deprive you of everything (and
Allah is High above this), He would not be unjust to you. سبحانه.
However, it is Allah Himself Who decreed upon Himself to reward His righteous slaves with Paradise. Allah ﷻ says:
جَنَّـٰتِ عَدۡنٍ ٱلَّتِی وَعَدَ ٱلرَّحۡمَـٰنُ عِبَادَهُۥ بِٱلۡغَیۡبِۚ إِنَّهُۥ كَانَ وَعۡدُهُۥ مَأۡتِیࣰّا
They will be granted the Gardens of Eden which the Merciful has promised to His servants, even though they have not seen them, and His promise shall be fulfilled.