Adam and Eve
You know the story: Eve was tempted by the snake to eat the forbidden fruit, and Adam following suit. From there, they were punished and banished from Eden. So how does this apply in Bleach? We know that Aizen had something to do with the increase of Hollow appearance in Kurakara town. This led to one of them attacking the Kurosaki residence in the first episode. Because of the Hogyoku inside her, Rukia has been weakened and was unable to kill the hollow. Thus, she was forced to turn Ichigo to a Shinigami – an act forbidden by the Gotei 13.
From then on, these two were forced to learn from the new world that they live in – Ichigo had to learn the ways of a Shinigami, and Rukia had to cope with living as a human. So right there, you can kind of relate it to how, once again, Aizen has indirectly played the Devil. He sent those Hollows to “tempt” Rukia and turn Ichigo into a Shinigami.
And from then on a chain of events ensued. Rukia got captured, which gave Aizen the opportunity to steal the Hogyoku. Ichigo got better and better because of both Soul Society and Aizen throwing obstacles at him. And all the while the Soul King, and probably Juha Bach, might have been watching and letting these events occur. Just like how the Christian God allowed Adam and Eve to eat the forbidden fruit.