Introduction
As Anglicans, we read the psalms a lot, once a month in Matins and Evensong. Others practice bible reading plans which at least get them through the psalms once a year. During this journey through the hymnbook of the Church, one will notice that there are harsh statements. For example, in Psalm 139 King David prays, "Wilt thou not slay the wicked, O God? Depart from me, ye blood-thirsty men...Do not I hate them, O LORD, that hate thee? and am not I grieved with those that rise up against thee? Yea, I hate them right sore; even as though they were mine enemies."
David often does this, where he prays for God's judgment and expresses "hatred" towards those who are wicked. These are called "Imprecatory Psalms." The question has arisen in Christian minds of how we are to take these. Are not these prayers against the command of Christian charity? Should we even still pray these Psalms anymore? Are these Psalms even inspired scripture or a mere historical account of the prayers of David?
This has lead to liturgical revisionism. The most famous instance of this is in the Roman Church in the "Pope Piux X Psalter." Multiple psalms were removed from the regular cycle of prayer of the church and verses from almost 20 more were removed. The same revision was done to the canticles prayed in the liturgy. Was this prudent?
St. Thomas Aquinas sheds light on this issue. He aids us in our interpretation of the imprecatory psalms in his Summa (ST.II-II.Q25.A6.Rep3). He gives us three ways of interpretation which this post will follow.
Prediction
First, these passages can be taken as predictions. This is especially related to those passages which focus on the end of the wicked. Rather than the Psalmist wishing damnation upon those who are evil, we can take it in the sense that the Psalmist is speaking about what will happen to the wicked. The example that St. Thomas uses is from Psalm 9. Rather than taking it in the sense that the Psalmist is wishing that the wicked are going to be "turned ito hell" (that is, judged to damnation), the Psalmist is predicting that the wicked "shall be turned to hell."
The Justice of the Punisher
Second, we may regard it as a wish, yet it is not in reference to the eternal damnation of man, but an exaltation of the justice of God. When there is a celebration of the destruction of the wicked, as is written in Psalm 57, "The righteous shall rejoice when he seeth the vengeance," the destruction of man qua man is not being celebrated, but only the destruction and judgment of man in reference to God is being celebrated. This follows after the pattern of God's rejoicing. For, "God ....hath [not] pleasure in the destruction of the living.” Rather, the object of his rejoicing is in the expression of his justice, for "the just LORD loveth justice; his countenance will behold the thing that is just."
Towards Sin
Third, the reference of an imprecatory psalm is towards the removal of the sin of the wicked man and not towards the wicked man himself. For example, one may pray that a wicked king be judged who is causing death and mayhem (such as, let's say, pro-Abortion politicians). It is right and just to pray for this man to be destroyed and blotted out from existence for the end that his destruction ceases, or that he be judged severely and thus cease from his wickedness under the hand of God and repent.
Conclusion
In conclusion, as we have seen, there is no reason to remove the imprecatory psalms from the liturgy of the church. Rather, we ought to follow St. Augustine's advice in De Doctrina Christiana,
If the sentence is one of command, either forbidding a crime or vice, or enjoining an act of prudence or benevolence, it is not figurative. If, however, it seems to enjoin a crime or vice, or to forbid an act of prudence or benevolence, it is figurative...Scripture says: If your enemy hungers, feed him; if he thirsts, give him drink; and this is beyond doubt a command to do a kindness. But in what follows, for in so doing you shall heap coals of fire on his head, one would think a deed of malevolence was enjoined. Do not doubt, then, that the expression is figurative; and, while it is possible to interpret it in two ways, one pointing to the doing of an injury, the other to a display of superiority, let charity on the contrary call you back to benevolence, and interpret the coals of fire as the burning groans of penitence by which a man's pride is cured who bewails that he has been the enemy of one who came to his assistance in distress. In the same way, when our Lord says, He who loves his life shall lose it, we are not to think that He forbids the prudence with which it is a man's duty to care for his life, but that He says in a figurative sense, Let him lose his life — that is, let him destroy and lose that perverted and unnatural use which he now makes of his life, and through which his desires are fixed on temporal things so that he gives no heed to eternal. It is written: Give to the godly man, and help not a sinner. The latter clause of this sentence seems to forbid benevolence; for it says, help not a sinner. Understand, therefore, that sinner is put figuratively for sin, so that it is his sin you are not to help.