“Let the assembly of the peoples be gathered about you; over it return on high. The Lord judges the peoples; judge me, O Lord, according to my righteousness and according to the integrity that is in me.” – Psalm 7:7-8
David is pleading for the Lord to rise and judge the world. The singers of this psalm are submitting to the fact all men are answerable to God, not just the elect. David, in not pointing to his own righteousness and integrity, but that which is in him from his Father. This psalm calls for the judicial righteousness which can only be experienced in God judgement.
If, as disciples of Christ, we choose to sing this psalm we must do so with urgency. Not simply urgency for the judgement, but urgency for the reaching of the nations. To call for judgment on one hand and do nothing towards bringing grace to the lost on the other hand, is simply a cruel act. Only God is worthy to judge. Walter Zorn said, “Yahweh God must do what the gods do not do: bring justice to the nations.” Before the righteous judgement of justice is to be brought upon every tribe, those dedicated to God’s glory must take the truth of Christ to those tribes.
The mercy of Christ cannot be selfishly kept by Christians. The Lord’s disciples must show the compassion found in the blood of Christ to the world, as it has been shown them. It is despicable and reprehensible to keep the truth from the lost. Taking no action is choosing sides. As we decide to do nothing to reach the lost we swing the axe no less than the executioner does. Our call for judgment and lack of evangelism is repugnant to the Lord of the harvest. Certainly, we want our Father to judge. Only he is worthy and capable of doing so. His judgement is not harsh, but full of justice. The disciples of Jesus must pray for that judgment to come quickly, but not one moment before we have done all we can to take his love to the nations.
 S. Edward Tesh and Walter D. Zorn, Psalms, The College Press NIV Commentary (Joplin, MO: College Press, 1999), 116.