From the Quran

Allah the Exalted said: (The Prophet believed in what was revealed to him and the believers did; All believed in Allah, His angels, His books and Messengers) (Noble Qur’an 2:285)

Allah the Exalted said: (and whosoever disbelieves in Allah, His Angels, His Books, His Messengers, and the Last Day, then indeed he has strayed far away) (Noble Qur’an 4:136)

Allah the Exalted said: (Verily, We have created all things with Qadar (Divine Preordainments)) (Noble Qur’an 54:49)

From the Sunnah

Omar said: (“While we were sitting with the Messenger of Allah one day a man came up to us whose clothes were extremely white, whose hair was extremely black, upon whom traces of traveling could not be seen, and whom none of us knew until he sat down close to the Prophet so that he rested his knees to his knees and placed his two hands upon his thighs and said, oh Muhammad, inform me about Islam.

The Messenger of Allah said: Islam is that you witness that there is no deity worthy of worship but Allah and that Muhammad is the Messenger of Allah, and you establish the Prayer, and you give the Zakat, and you fast Ramadan, and you perform the Hajj to the House if you are able to make a way to it. He said: You have told the truth, and we were amazed at him asking him and [then] telling him that he told the truth.

He said: Inform me about Iman. He said: That you believe in Allah, His angels, His books, His Messengers, and the Last Day, and to believe in the Divine Decree, the good of it and the bad of it. He said: You have told the truth.

He said: Inform me about Ihsan. He said: That you worship Allah as if you see Him, for if you don’t see Him then truly He sees you.

He said: Inform me about the Hour. He said: The one asked about it knows no more than the one asking.

He said: Then tell me about its sign. He said: That the female slave should give birth to her mistress, and you see poor, naked, barefoot shepherds of sheep and goats competing to make tall buildings.

He went away, and I remained for some time. Then he asked, Omar, do you know who the questioner was? I said: Allah and His Messenger know best. He said: He was Jibreel (Gabriel the angel) who came to you to teach you your Deen (religion).”) (Muslim)