Malachi highlights the special bond the Israelites have with each other, because of the special bond they share with God. Malachi points out that they are all brothers and sisters who belong to the same family of God. Because they all belong to the same family, surely they ought not to treat each other as they were. The special bond as brothers and sisters of the same Father should incite them to love one another.
10 Have we not all one Father? Has not one God created us? Why then are we faithless to one another, profaning the covenant of our fathers?