The Torah tells us that Adam was created in the divine image (Gen 1.26-27; 5; 9.6). If the divinity had a body, then we would suppose this means that Adam was created as the divinity's Doppelgänger, but a corporal deity is foreign to both tradition and reason so the Torah must have something else in mind. I have seen several interpretation of Adam's divine image, but perhaps someone might be so kind as to summarize the major opinions in a convenient list for the enlightenment of all.
I have seen the following interpretations:
Immortality (Book of Wisdom)
Chosen by the creator for special dignity (Saadia Gaon)
Dominion over the earth and all its inhabitants (Saadia Gaon)
ֹAngels and other divine beings appear like noble humans to the prophets as humans are the closest things to angels imaginable (Judah Halevi)
Free will (Jacob ben Wolf Kranz)