We looked at the Prophets and their look at social issues and mercy a while back from the perspective of Theodore Laetsch. In their proclamation of Law they understood that only the Gospel can motivate.
“The prophets knew that this Gospel was the only means whereby a people could be called into existence that would be willing and able to comply with the high social standards set up by the God of holiness for His chosen nation. Therefore they were not satisfied with mere denunciation of social ills, with demanding justice and mercy and humility, nor even with what manner of outer social reform they might have attained. God was not satisfied with anything less than a change of heart, and a change of heart effected by faith in His Son as the promised Redeemer, and also the prophets were satisfied with nothing less. They would think of changing God’s plan as little as they would think of changing God’s demands. In the very center of the social order proclaimed by them as the will of God for His people stood the Woman’s Seed, the Messiah, the suffering Servant, and His vicarious death, from whom radiated strength and willingness into the hearts and minds and members of the believers to live up to the demands of this social code, constantly progressing in justice, increasing in mercy, growing in humility.”