There are seven things which are essential for a Muslim to believe in. These come under the heading of Iman Mufassal, which requires a longer, more detailed declaration of faith. They are to believe in God, in His angels, in His revealed Book, in all of His messengers, in the Last Day (the Day of Judgement), in Taqdir, (the doctrine of predestination, which means that everything good or bad is decided by God), and in Life After Death.

Source: The Man Islam Builds