It is narrated on the authority of Abu Ayyub that a man came to the Prophet (Peace Be upon Him) and said: "Direct me to a deed which draws me near to Paradise and takes me away from the Hellfire. Upon this, the Prophet (PBUH) said: You worship Allah and never associate anything with Him, establish prayer, and pay Zakat, and do good to your kin. When he turned his back, the Messenger of Allah (PBUH) remarked: If he adheres to what he has been ordered to do, he would enter Paradise."
Sahih al-Bukhari (1396), Sahih Muslim (13)