The Law of Moses was absolutely clear; Deuteronomy chapter 22, verses 23 and 24, reads:


“If a man is found sleeping with another man’s wife, both the man who slept with her and the woman must die.”


The situation for Joseph was painfully distressing; he’d discovered his fiancée, Mary, was pregnant - what should he do? Matthew’s account of the birth of Jesus tells us that Joseph was a just man, faithful to the Law of Moses (chapter 1, verse 19). He was upset (“considered” of verse 20 can be read as “became angry”) and this is understandable, as is his desire to separate from Mary.


Despite the plain reading of the Law, Joseph had a deep appreciation of God’s heart which lies behind that Law. God’s justice isn’t primarily about retribution, it’s about making things right. In his commentary on Isaiah chapter 43, Alec Motyer writes,


“Only God knows how holiness and pardon co-exist in the divine nature. ... No connecting word in human vocabulary can bring these two realities together.”


(We see an example of this holiness and pardon at work with the woman caught in adultery in John chapter 8). And so Joseph initially intended to divorce Mary quietly so she wouldn’t face public disgrace.


As with Mary, an angel appeared to Joseph with a personal message:


“Joseph son of David, do not be afraid to take Mary home as your wife, because what is conceived in her is from the Holy Spirit. She will give birth to a son, and you are to give him the name Jesus, because he will save his people from their sins.”


This promise to Joseph shows that God’s merciful justice runs even deeper than he could possibly have imagined. Through the Christ-child Mary was carrying, God would, on the cross, bring about both eternal justice and mercy at the same time.


On the cross, Jesus took in his body what we deserve to give us something we don’t deserve. On the hill of Calvary, the salvation of the world from its deathly and fatal entanglement with sin and evil was wrought; forgiveness and reconciliation were made freely available to anyone who will receive it by faith.


God’s justice was fulfilled and all things were made right - for all eternity. Followers of Jesus cannot overlook or excuse sin, but they are called, as Joseph was, to the kind of merciful justice that makes things right.