How to become a Shiite
Just as if a person believes in monotheism, prophecy, and resurrection, and says:
I bear witness that God is one and Muhammad sent him, he becomes a Muslim, Shiites believe that except for the above three principles, a Muslim must believe that God is just. That is, if God has given many blessings to someone, and has not given those blessings to anyone, but in this world he has suffered from dozens of diseases and afflictions. God will compensate him on the Day of Resurrection. Therefore, the trial of a person has a more difficult blessing. And the other case is that the Shiites believe that God has appointed Ali (AS) as the successor of the Prophet. Should say: La Ellaha Ellah Allah and Muhammad Rasul Allah and Ali Wali Allah.