Imām Ibn Qayyim Al-Jawziyyah (died 752H) stated:
“The two
feet of a person who stands before Allāh
on the Day of Resurrection will not move until he is asked regarding two
matters: “What was it that you worshipped? What was your response to
the Messengers? “The answer to the first question is by the actualisation of
the words, none has the right to be worshipped except Allāh
alongside knowledge, affirmation and action. The answer to the second question is
by the actualisation of the words, Muhammad is
the Messenger of Allāh alongside knowledge, affirmation, submission and
obedience.
Zādul-Ma’ād (1/37), Mu’assasatur-Risālah edition.
Taken from: https://abukhadeejah.com/the-three-fundamental-principles-of-islam-and-their-proofs-ebook-pdf/