Imam Hassan Askari (pbuh) considers his followers to be his close family, and says, “There is a close family relationship between you and us.” This means that we are like close family members; like father and child, like brothers. A believer is the brother of another believer. That is, the relationship between two believers is that of brotherhood, as in having the same parents, not even like half-brothers. What is meant by a believer? The person who follows the way of Imam Hassan Askari (pbuh). This is the strong organizational relationship between the Imam (pbuh) and his followers.
Ayatollah Khamenei, 1972