When Imam Abu Hanifa (may Allah have mercy on him) was asked the belief of Ahl-us-Sunnah wal-Jama’aha (those Muslims who are correct in their Deen by holding on to the Sunnah and ways of the Sahabah), he answered:
We give preference to the Shaikhain (the two elders), Abubakr and Umar
We love the Khatanain (the two son-in-laws), Uthman and Ali
We believe in wiping over Khuffain (leather socks) for Wudhu
These three beliefs are clearly and emphatically proven from the Sunnah. Many of the deviant groups that existed early on and still continue to exists have gone astray due to their disrespect for any one or more of the Khulafa Rashideen. Muslims love and respect all four. They were the best of this Ummah and worked together so that Islam could flourish across the world. May Allah Almighty reward them on our behalf. Aameen.