It is narrated from Sayyiduna Ali (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "No person can be a complete believer until he believes in four things: he believes in Allah, and that He has sent me as a true Prophet, he believes in being raised after death, and he believes in good and bad destiny."
Hadith Referenceمسند احمد / مسند الخلفاء الراشدين / 1112
Hadith Gradingحکم دارالسلام:إسناده فيه رجل مبهم، وقد مضى برقم: (708) ..... عن ربعي بن حراش عن علي دون واسطة الرجل المبهم، وصحح إسناده أحمد شاكر