In Matt. 5:6, Jesus said, “Blessed are they which do hunger and thirst after righteousness: for they shall be filled.” “Hunger” and “Thirst” suggest a human craving for food and drink. However, in this scripture, Jesus is not referring to food and drink, but a hunger and thirst for righteousness, which is “the character or quality of being right or just.” Righteousness is an attribute of God that signifies his justice, holiness, and to be free from sin. Those who have this strong desire to know God, will be led to an understanding of his great Justice and loving Plan of Salvation, as Jesus said in Matt. 7:7,8, “Ask, and it shall be given you; seek, and ye shall find; knock, and it shall be opened unto you: For every one that asketh receiveth; and he that seeketh findeth; and to him that knocketh it shall be opened.”
When Adam sinned against God, he became unrighteous, as the Apostle Paul tells us in Rom. 3:10, “As it is written, There is none righteous, no, not one.” There is only one way to approach God, as Jesus said in John 14:6, “I am the way, the truth, and the life: no man cometh unto the Father, but by me.” In John 6:32,33,35, Jesus said, “My Father giveth you the true bread from heaven. For the bread of God is he which cometh down from heaven, and giveth life unto the world. … I am the bread of life: he that cometh to me shall never hunger; and he that believeth on me shall never thirst.”
Water is a symbol of truth and Jesus speaks of “living water” as a gift of God in John 4:10-14: “But whosoever drinketh of the water that I shall give him shall never thirst; but the water that I shall give him shall be in him a well of water springing up into everlasting life.”
To hunger and thirst after righteousness is to hunger after the righteousness provided through faith in Jesus, and apply the water of truth to cleanse us from all unrighteousness.