From its very first lines, the biblical narrative deals with the theme of fraternity and it does so with a dose of crude realism. Being siblings is not an easy task and the bond of blood is insufficient to indicate the quality of a relationship. In the second creation narrative God says: “It is not good that Adam should be alone” (Gen 2:18). Thus the woman is created as a helper, so that she and Adam may be face to face, on the same level without either one of them dominating the other (cf. ibid). In this manner the Lord points the way for an authentic, salvific and fruitful relationship, which comes from two people being together, each being different but complementary.
To emerge out of solitude, however, also means facing the problem of a confrontation or clash with the other. In fact, from the outset the story of the first two brothers (cf. Gen 4:1-16) is one of hierarchies and preferences, which do not allow one to see in the other a brother, but rather a competitor and an adversary to be eliminated. It is for this reason that it is surprising how the story of the first pair of brothers is presented from the point of view of the guilty one, that is, of Cain, who, by killing Abel, also eliminates the possibility of defining himself as a brother. Moreover, in the biblical account we do not see any justification of the murderer, as for example, in the story of Romulus and Remus, but the serious responsibility of the murderer is highlighted in an authoritative way by God.