Fundamentals of iman are six. These fundamentals are explained in the Amantu prayer. Rasulullah “sall-Allahu ’alaihi wa sallam” said that iman means believing in six certain things. Therefore, every Muslim must teach (Amantu) to their children and make them memorize it.
AMANTU: (Amantu bi’llahi wa Mala’ikatihi wa Kutubihi wa Rusulihi walyawm-il-akhiri wa bil-qadari, khairihi wa sharrihi min Allahi ta’ala walba’thu ba’d-al-mawti haqqun, Ash-hadu an la ilaha illallah wa ash hadu anna Muhammadan ’abduhu wa rasuluhu.).