Jannah becomes obligatory for the one who Recites the following

Abu Sa’id (Ra) said that Rasullallah (Peace be upon him) said, “Whoever says: Radeetu billahi rabban, Wa bil-Islaami deenan, Wa bi-Muhammadin rasoolan Jannah becomes obligatory for him (to enter).
(Abu-Dawud)

– Best said in Morning and Evening with “Nabiyan wa rasoolan”