We have the verse Micah 6:8 - "And what does the Lord require of you? To act justly and to love mercy and to walk humbly with your God" - on a plaque in our home. While doing some study regarding the meaning of this verse, I found helpful what Cyril Spaude write in the "People;s Bible."
Act Justly. Act accordingly to God's standard of justice and laid out in His Law. Worshipping God alone and not idols, trusting in Him alone and not in weapons, acting justly to one's fellowman is showing him no injustice or cruelty in word or deed but treating him like oneself.
Love Mercy. This God's kind of mercy. It's the love He shows to us, a forgiving, compassionate love, an unselfish, giving love. The father of the prodigal son had it; he welcomed back his son with open arms. The good Samaritan showed it to the hapless victim on the road.
Walk Humbly. God-pleasing humility is found only in the presence of the holy and just God. When man sees himself as God sees him, a sinner deserving death, then he will humbly see God's forgiveness in Christ and gladly seek His help to live a godly life according to His will.
Micah 6:8 is really an epitome of the entire Law, of both tables which show man's duty to God and his duty to his fellow man. See Matthew 22:37-40.
Repentant faith in the Savior is the basis for showing justice, mercy and humility as God requires. Faith gives us the reason and the gospel gives us the strength to love the Lord our God above all else and our neighbor as ourselves!