Sahih Muslim | Book 1 | Hadith Number 43

Narrated by Ubadah b. Samit
It is narrated on the authority of Ubadah b. Samit that the messenger of Allah (may peace be upon him) observed: He who said: "There is no god but Allah, He is One and there is no associate with Him, that Muhammad is his servant and His messenger, that Christ is servant and the son of His slave-girl and he (Christ) His word which He communicated to Mary and is His Spirit, that Paradise is a fact and Hell is a fact," Allah would make him (he who affirms these truths enter Paradise through any one of its eight doors which he would like.