Number one:

Belief in Allah as the one and only God.

Number Two:

Belief in angels.

Number Three:

Belief in the holy books.

Number Four:

Belief in the Prophets... e.g. Adam, Ibrahim (Abraham), Musa (Moses), Dawud (David), Isa (Jesus). ...

Number Five:

Belief in the Day of Judgement... ...

Number Six:

Belief in Predestination...