How should one deal with a person who identifies as a Shiite, but shows no verbal or practical innovation that contradicts the methodology of Ahl al-Sunnah?

The Shīʿah are various sects and schools of thought. Some of them believe in the distortion of the Qur’an, revile the Companions, and worship the dead, while others are less extreme. Some individuals may associate with them without knowing their doctrine or caring about it, and some of them may practice taqiyyah (dissimulation). Dealing with someone who does not outwardly display the innovations of the group should involve respecting the apparent rights of a Muslim, such as greeting him with salām, visiting him when he is sick, and attending his funeral, while gently inviting him to the methodology of the Ahl al-Sunnah regarding Tawḥīd (monotheism), the divine attributes, the Qur’an, and the Companions, at the hands of a qualified person.