Can someone please explain the end of Fullmetal Alchemist?

In the ending of the Fullmetal Alchemist, Bradley was confronted by Roy Mustang. He revealed to him that he is hungry for power to atone for the crimes he committed yet he also has a desire to not doing the (evil) things again. The meaning of alchemy was also explained where a broken fragment of a teacup can turn into a teacup as long as it has the same composition of the original object.

Mustang’s sight was also restored with the use of the Philosopher’s stone. He got blind because he was sacrificed in the portal but because it was not a punishment when he lost his sight, he was offered for his sight to be restored in the ending.

The fact that our world is connected to Ed's world is foreshadowed by Ed when he first brings up what he saw that night, they show the gate which has a design based off of a real sculpture titled, "The gates of Hell" in Dante's Inferno where hell goes through the world and then comes out the other side. This means that there must be another side to the gate.

Then Hoenhime says that the humunculi come from the other side of the gate and then it is shown to be our world. After understanding the meaning of the gate, you have to look into Edward Elric's progression through the anime which underlines the main point of the anime, religion is a lie and life is not fair.