The fourth characteristic, hungering and thirsting for righteousness, describes the God-given inward longing that every true born-again person possesses. He is grieved by unrighteousness in the world and in himself. He hates sin (see Ps. 97:10; 119:128, 163) and loves righteousness.
Too often, when we read the word righteousness in Scripture, we immediately translate it, “the legal righteousness imputed to us by Christ,” but that is not always what the word means. Quite often it means, “the quality of living right by God’s standards.” That is obviously the meaning Jesus intended here, because there is no reason for a Christian to hunger for what he already possesses. He already has an imputed righteousness. Those who have been born of the Spirit long to live righteously, and they have assurance that they will one day “be satisfied” (Matt. 5:6), certain that God, by His grace, will complete the work He’s begun in them (see Phil. 1:6).
Jesus’ words here also foresee the time of the new earth, “in which righteousness dwells” (2 Pet.3:13). Then there will be no sin. Everyone will love God with all his heart and love his neighbor as himself. We who now hunger and thirst for righteousness will then be satisfied. Finally our heart-felt prayer will be fully answered, “Your will be done on earth as it is in heaven” (Matt. 6:10).