The sins that cry to heaven for vengeance are: Wilful murder, sodomy, oppression of the poor, defrauding labourers of their wages. This category of four grievous sins is not a class of the worst possible sins, for none of them are opposed directly to God, but of sins that must provoke God's anger in a way that we do not attribute to His Divine anger against many other sins, and because Holy Scripture speaks of them as a class apart and as crying to God for vengeance.
In the four sins mentioned above, the offence is directly opposed to nature and natural instincts, and therefore to the order in this world which God has taken supreme care to establish. Thus, wilful murder is directly opposed to God's sovereignty, Who alone is master of life; sodomy is a perversion of the true natural sexual instinct, which is designed to perpetuate the race; oppression of the poor extinguishes the ingrained sense of pity in the human heart; defrauding labourers of their wages is opposed to the social instinct that safeguards the property of the members of the body politic. It is obvious that these sins tend to the destruction of the human race.There is good warranty in Holy Scripture for putting these four sins in a class apart and considering them very heinous crimes. Thus : “The voice of thy brother crieth to Me from the earth;” “The cry of Sodom and Gomorrah is multiplied, and their sin is become exceedingly grievous;” “I have seen the affliction of my people in Egypt, and I have heard their cry because of the rigour of them that are over the works;” “Behold the hire of the labourers, who have reaped down your fields, which by fraud has been kept back by you, crieth; and the cry of them hath entered into the ears of the Lord of Sabbaoth” (Gen. 4, 10 : 18, 20 : 19, 13; Exod. 3, 7 ; Deut. 24, 14 ; Jas. 5, 4). [Rev. Henry Davis, S.J., Moral and Pastoral Theology, 4th ed. (New York: Sheed and Ward, 1943), pp. 214-15].