Inflation is a belief that the universe expanded completely outside the rules of physical laws, and that at a certain period it stopped expanding, without knowing why it expanded, and why it stopped expanding. There are no physical laws, there are no laboratory models, nor rules that can be shown in laboratories that prove inflation.
Thus, it is merely a belief that inflation of the universe can occur. Simply put, scientists say it happened. The system is the same parallel to religious beliefs in which it defines that God made things. The inflationary system was created by scientists so that certain Big Bang problems could be solved. Thus, inflation is like a god to solve the Big Bang problems.
