The default faith of the Scripture is that God takes care of His people in every sense. He forgives all their sins, heals all their diseases, rescues them from destruction, crowns them with lovingkindness, and renews their life with vigor (Psalm 103:1-4). However, when the complete context of the entire Bible is taken into account, we find out that there were times when God did not heal every every disease in this life. The five benefits of God's care listed in Psalm 103 should each individually be understood in light of the whole Scripture.
For example, Christ doesn't heal a Christian when it's time for them to go to heaven (Psalm 139:16). It's obvious from practical experience that Christ doesn't heal every Christian of everything, because all Christians age, get sick, their bodies die, and they go to be with the Lord. Sin's curse still rests on this material world, in spite of Christ's death. The earth still groans. Christians groan with it (Romans 8:22-23). There were a few extraordinary cases in Scripture where a believer got to go to heaven without dying (Enoch, Elijah), but the rest of us age, wear down, and most of us will die of natural causes.
The Lord doesn't heal when he is punishing sin. King Uzziah sinned grievously by intruding into the sacred role of the priests. Uzziah should have known better! In fact, he did know better, which is why God smote him so sternly. I do not doubt that God forgave Uzziah, but the text says God never took the leprosy away (2 Chron. 26:27). God could have healed Uzziah (He did for Miriam in Numbers 12:10-15), but He did not. Uzziah died a leper.
Any sin can be forgiven, but the punishment of the sin might remain. Sin , especially sin by a leader, always carries serious consequences, and some of those consequences involve physical ailments. Paul said in 1st Corinthians 11:30 that some of the Corinthian congregation were weak and sick, and some had died, because of their selfish mistreatment of others in the flock and the way they dishonored the Lord's Table.
Christ doesn't heal while He is testing faith (Job 1-2). Not every sickness is punishment for sin, and we commit the sin of Job's judgmental friends if we assume this. It's a sin to just automatically assume a sick Christian is in unbelief or did something wrong. God Himself, in Job 1, said Job was a man of excellence, guiltless, so teachings that Job somehow brought his illness upon himself are wrong. Rather, God was vindicating His own praise of Job's faith, and shaming the devil for claiming Job was a religious mercenary, although Job never knew that (and God didn't tell him).
James 5:11 promises God will reward us as we come through His tests in faith. Job's example shows us that illness is one of those tests, along with natural disasters (lightning killed some of Job's herds, a windstorm collapsed a house on his children) and crime (gangs of thieves murdered Job's workers and stole all his flocks). But the Lord eventually stops the test, and rewards the believer.
Christ doesn't heal the payback for foolishness. Not everything bad is from the devil. Some of our problems are self-inflicted. Proverbs 3:18 says wisdom is a tree of life and blessing, so what fruit do you imagine foolishness grows? Elsewhere in Proverbs, Solomon says that drunks get bruises, lazy people get poverty, adulterers get beaten up by jealous husbands, and schemers fall into the pits they themselves have dug. Christians could catch AIDS because of immorality, and they shouldn't count on Christ miraculously healing them of it.
Christ knew not to throw Himself off the temple mount on the notion that God would catch Him, because you don't try to force God's hand by deliberately doing stupid, reckless things (Luke 4:9-12). Christ will let us live with the physical consequences of our own foolishness.
Christ doesn't take away the physical scars of persecution. In Galatians 6:17, Paul reminded his readers he still carried in his body the scars of Christ -- referring to wounds left on him by persecution. Paul suffered physically in his service to Christ. In 2 Corinthians 11:25, Paul said he had been pelted with stones and beaten with rods for the Gospel. He still had those scars. Christ allowed Paul to carry those badges of faithful honor in his body, like the medals of a military hero.
Psalm 103 doesn't contradict these other passages. Instead, we take them all side-by-side, believe all of them, and, with the help of other sound Christian teachers and thinkers, think through the best way to harmonize them. Unlike the saving forgiveness of sin, God makes certain exceptions to His normal, default work of ministering to His people's diseases. In the end, all of God's people will be forever immortal, vital, and whole through the redeeming work of His Son.
Recently, Dr. John MacArthur made a statement on social justice which, to my mind, was inadequate and reactionary. On the other hand, I dislike the current habit of fellow evangelicals to quote Martin Luther King Jr., as if he was a reliable guide on justice (due to his liberal disrespect for Scripture, he was not). But what does "social justice" even mean? People bat that phrase back and forth, often plunging into specific topics, but often without defining basic terms.
God is the ultimate basis of justice. The community isn't the basis of justice, neither is individual intuition. Justice exists because God exists. If there is no God, or if God hasn't spoken, then there is no justice. There can be no justice in an atheist world.
God has already spoken definitively about justice in the Bible. The Bible is God's out-breathed word, without error over-all, and in each individual part. This makes it the highest authority.
The Bible defines what is just, and the Bible's definitions of justice are sufficient for all peoples at all times. The Bible does not need to be supplemented by human reason, and is not defined or evolved-past by human culture. Sociology, law, and economics do not define justice, the Bible does.
The Torah states rules of justice in both narrative and prescriptive ways. Genesis tells many stories in which many characters act unjustly. God held them accountable for their unjust acts, even though Moses hadn't written his law yet. Then God gave His written law through Moses.
In the pursuit of clear rules of justice, Moses' Law must be handled with extreme care. Christians have erred toward theocracy (such as Rousas Rushdoony) by applying all of Moses' laws to Gentile societies, which is incorrect. On the other hand, other Christians (such as J. H. Thornwell) preached the exclusive "spirituality" of the church, and that Christianity had nothing to say to the civil society and laws of its own times. This too was wrong.
I believe that nine of the ten commandments can be seen in the stories of Genesis, and the New Testament gives us guidance on which portions of Moses' Law were timeless versus which ones were discontinued; and which of Moses' laws illustrated justice at work. For example, Moses forbids the moving of boundary-stones. This was an example of the timeless law, "Do not steal." We don't use boundary-stones today, but the principle would be not to steal by altering ownership markers.
The New Testament is clear that the entire priestly system of Moses was fulfilled by Christ, and is obsolete. Only Israel was supposed to be God's real theocracy. Christ said the Mosaic food laws were no longer in force. God gave the blessings and cursings of the Law for the Hebrews as they dwelt in the Promised Land. The Puritans, misguided by their "replacement theology" errors, never had the right to claim them. The U.S. was never the New Israel.
I believe God governs the 'secular' world by the general moral laws we see in Genesis. Another way to describe these laws is "conscience."
God affirms the right of non-theocratic governments to exist, both during Israel's time in Babylon (where God tells the Hebrews to be a blessing to the city), and in Romans 13 (where Paul says God appoints the secular rulers and requires us to respect and obey them within certain limits).
This is why the absence of blue laws doesn't bother me in the least. The Fourth Commandment (Sabbath) was only for the Jews, was only for the seventh day, and was fulfilled in Christ. God never expected Gentile nations to keep the sabbath, not even in the Old Testament times.
My bottom line is that true standards of justice are defined by the Bible. The Bible affirms the basic, universal instincts of conscience (even bad people object when evil acts are done to them!). It is a sin to falsely define "justice" by an unbiblical philosophical authority, such as Ghandi, Rousseau, or Marx, then try to Christianize those definitions with verses -- almost always quoted out of context.
So, please don't be wildly swept along by the passionate purveyors of politics. Political theories of justice, social or otherwise, fall under the dissecting sword of Scripture as much any religious sermon does. Scripture alone, studied carefully, defines the fundamental laws of justice. Not sociologists, economists, or philosophers.