How does the author use foreshadowing in Demian?

In Chapter Five, Demian's note to Sinclair is an interpretation of his painting. He envisions Sinclair's dark globe as an egg from which Sinclair is emerging. He realizes that Sinclair is breaking his ties with the belief system he inherited from his family. Demian's message acknowledges this and foreshadows the next stage in Sinclair's development. He mentions the god, Abraxas, who contains both divine and satanic elements, and happens to be the subject matter for the day's lecture. This is a god who seems to meld Sinclair's two worlds – the good one and the evil one. The concept excites him because it could provide a peaceful resolution to his struggle.