These related terms—justification, atonement, and scapegoat—are connected in a Christian sense in the living, holy victim, Jesus Christ, “whose blood has become the instrument and atonement” (CCC, 1992) for our sins. Justification is given to Christians in Baptism, the sacrament of faith.
The term scapegoat is an Old Testament term (see Leviticus 16) connected with a goat sent out into the wilderness after the Jewish priest had symbolically laid the sins of the people upon it. Covenant renewal and restoration of the people were connected to the Day of Atonement (Yom Kippur).
Several study questions are available online.