When is a person considered to be upon the Sunnah?

بسم الله والحمد لله والصلاة والسلام على رسول الله ، وبعد

Sahl bin `Abdullaah al-Tustaree رحمه الله was asked: How can a person know that he is following (Ahl) al-Sunnah wal-Jamaa`ah?

He said: “When he finds for himself ten characteristics:

1. That he does not abandon the Jamaa`ah.

2. And that he does not reviles Companions of the Prophet صلى الله عليه وسلم.

3. And that he does not revolt with (i.e. raises) the sword against this Ummah.

4. And that he does not belie (deny) the Qadr.

5. And does not doubt in (the articles of) Imaan.

6. And that he does not argue in (regards to the matter of) the Deen.

7. And that he does not abandon offering the Salaah (al-Janaazah) for anyone who died from the People of the Qiblah (i.e. the Muslims) due to a sin (which the deceased might have committed).

8. And that he does not abandon wiping over the Khuffs (shoes/socks).

9. And that he does not abandon the (Salaah in) congregation behind a pious or a sinner.”

[Sharh Usool I`teqaad (1/205/324) of Laalikaaee. This is how only 9 points are mentioned]