Can we pray for justice, and yet love our enemy at the same time? The answer is yes…We will magnify the mercy of God by praying for our enemies to be saved and reconciled to God. At the personal level we will be willing to suffer for their everlasting good, and we will give them food and drink. We will put away malicious hatred and private vengeance. But at the public level we will also magnify the justice of God by praying and working for justice to be done on earth, if necessary through wise and measured force from God-ordained authority.
John Piper