In the season finale of "Preacher," Jesse Custer (Dominic Cooper) will perform a miracle that will be known to the whole world.

The new sneak peek for episode 13 was just released. It showed Custer in a classroom full of school children being spoken to by a nun who tells them not to misbehave, but to watch Custer perform an unexpected miracle.

The nun tells the children that the preacher is not God exactly, but someone who is close to Him. Herr Starr (Pip Torrens), leader of the Grail watches at the back as he prepares to record the miracle. Then Custer walks to the front and surveys the crowd of kids. He is about to do an amazing feat when the sneak peek ends.

It remains to be seen what the supposed miracle is and the effect it would have on those who watch it. Another miracle was showcased in episode 7 where a pig floated a few feet above the ground in Vietnam. The incident became an instant sensation which prompted Starr to go there and investigate.

In order to keep the "flying pig" miracle from spreading, Starr opted to murder the whole Vietnamese town by polluting its water supply. He believed that the only miracles that were allowed to be performed were by the Messiah who Starr had kept in his custody.

However, God's progeny turned out to be mentally challenged because of the inbreeding, which is why Starr persuaded Custer to become the Messiah instead. The preacher's Genesis power that allowed him to control other people's thoughts and actions were the right recipe to become a replacement Messiah for the meantime.

The next episode will seemingly unveil Custer as the substitute Messiah when he performs the miracle in front of the classroom full of kids.

"Preacher" season 2 episode 13 will return on Monday, Sept. 11 at 9 p.m. EDT on AMC.