Can personal morality overcome social immorality? Can godly individuals change a group's brutality?

Reinhold Niebuhr, in his 1932 classic on ethics & politics, Moral Man and Immoral Society, considered both liberals & conservatives to be “naïve optimists” about changing personal or social evils. Can I be a “realist” (neither minimizing evil in human nature nor maximizing the possibility of change)? Can I hope for gospel change in individual lives and in society? Can personal morality overcome social immorality?

Our fellow citizens are more secular and hostile to traditional Judeo-Christian teaching and ethics. Ours is a post-Christian society. Believing citizens struggle to hold on to their religious teachings while treating fellow citizens in a civil and respectful manner. Biblical definitions of justice, marriage, and sexuality as held by church courts are set against autonomous freedom, individual identity, and personal rights in civil law courts.

Followers of Jesus and members of Christian churches may fear a pluralistic society for us and our children. And those fears may motivate us to resist social changes by legal and political means. I've been ruminating. This summarizes my thoughts:

Q. Can a nation's Civil Laws reflect God's Moral Laws?
A. Yes, but only imperfectly in this immoral, sinful world.

Q. Can a nation become Moral through Political means?
A. No. Individual Christians with the political liberty to choose their leaders can and should be political activists (the early Christians and those living under repressive regimes cannot). But, when churches are politicized, Jesus' followers are no longer witnesses to the new life and the new society that is in Christ, but can become partisans who police the morality of their fellow citizens.

Q. How, then, can a nation and a society be transformed?
A. If Jesus' followers live as "salt and light" (preserving from decay and promoting truth) and use the "weapons of the Spirit" (God's truth and self-sacrificing love), fellow citizens may be convinced, converted, and compelled to change laws. But personal renewal and church revival always precedes social reform.

Q. What, then, is my ultimate hope for a good and just society?
A. At his return, Jesus will consummate God's New Creation which is only now begun in his followers ("now spiritually present, but not socially complete"). Today, Jesus' church is called to be a foretaste and witness of that coming Day, by serving others as kingdom ambassadors and local embassies.