In Gen 15:16, what does it mean that "the iniquity of the Amorites is not complete"...is this related to "fill up the measure of their sins" 1 Th 2:16

The iniquity of the Amorites...Fill up the measure of their sins Let us deal with the headline question.

It should be noted first, that both references are dealing with nations as a whole. (1) the AMORITES occupied the land of Canaan, which God had promised that Abraham and his descendants would inherit. (Genesis 14:14-17) But God knew the tendency of men in nations to become depraved as centuries roll on. Of course, God is patient and merciful, and wanting all to come to repentance. (Thus the story of Jonah and the Ninevites illustrates.) But the Canaanites were persistent in their wickedness. And there did come a time when "the iniquity of the Amorites became complete...crossed over the line of no-return...reached the point where, out of mercy, God had to make an end of their ways. Sexual diseases were rampant, innocent blood was flowing in the streets, children were sacrificed to idols, social justice was a thing of the past. God had given them approximately 400 years to repent, but it was to no avail.

(2) The Israelites of the old Testament should have learned about civility, morality, and righteousness from the ancient history of their forefathers. But instead they fell into the same waywardness of the nations before them. The sins of Israel reached the brim of the cup of wrath! (2 Kings 22-25) They acted just as wickedly as the pagan nations around them. And it came to the point where it was declared: the LORD was not willing to forgive. (2 Kings 24:5) They had "completed their iniquity" just like the Amorites, and were kicked out from the land (586-7 B.C.) The Temple destroyed, Jerusalem razed, the preple taken captive.

(3) The people of JUDEA still did not learn the correlation between civility and destiny...between social justice and endurance as a nation. The sins of Israel in the first century also came to a head, with no hope of repentance. Crime, greed, sacerdotal hypocrisy, murder,...had become the new norm, so Jesus Himself had to declare: Look, your house is left to you desolate.

Woe to you teachers of the Law and Pharisees, you hypocrites! You build tombs for the prophets and decorate the graves of the righteous. And you say, "If we had lived in the days of our forefathers, we would not have taken part with them in shedding the blood of the prophets." So you testify against yourselves, that you are the descendants of those who murdered the prophets. Fill up, then, the measure of the sin of your forefathers! (Matthew 23:29-32)

This wording of Jesus is equivalent to the phrase used to describe the Amorites. [And the sin was "filled up" by the Jews crucifying, and shedding the blood of the greatest of the Israeli prophets, Jesus.] And just as Judgment had come upon the Amorites...and the O.T. Israelites in 586 B.C....so the hammer of justice fell hard on the land of Judea with the ultimate Destruction of the Temple in A.D. 70.

(4) PAUL'S DECREE The reference to the incident mentioned in the Thessalonian letter refers to the opposition and persecution the Jew were heaping upon the Christians.

You, brothers...suffered from your own countrymen the same things those churches suffered from the Jews, who killed the Lord Jesus and the prophets and also drove us out. They displease God and are hostile to all men in their effort to keep us from speaking to the Gentiles so that they may be saved. In this way they always heap up their sins to the limit (fill up the measure of their sins). The wrath of God has come upon them fully. (1 Thessalonians 2:14-16)

In the same manner, Paul told how the rebellious people had crossed over the line and were ripe for judgment. Many interpret this as a reference to the horrid persecution the Roman emperor was imposing on the Jews at that time. Paul considered that treatment by the Romans as a judgment from God against those who were opposing the preaching of the Gospel.

Conclusion So, this phrase about "filling up sin" or "completing the iniquity" refers to any nation or people group that deserves judgment. It applies to their going beyond the point of repentance...beyond the hope of forgiveness.

First, Genesis and the Amorites is about historic events affecting ancient Israel one and a half thousand years before that letter to Christians in Thessalonica was penned. That letter spoke of people in the first century A.D. who had rejected Christ, particularly Jews who were forbidding Christians to speak to Gentiles about Christ.

Yes, both texts speak of a "measure of sin" being reached that would "trigger" as it were, God's judgment against both groups. It is possible that Paul - who knew the history of hostilities of the Amorites against the Jews - could have had that in mind. We do not know, but there's nothing unreasonable in wondering, or even supposing, that Paul might have.

When it comes to God's timing of bringing judgment against unrepentant sinners, it is astonishing just how patient he is. Yet, from a human point of view, most people take his patience to be a cause for complaint against him! Let it be noted, however, that God was dealing with an entire nation in Genesis, the Amorite nation that, as a nation, had shown hatred of God's people for many hundreds of years. In Paul's letter, hostility against Christians for preaching Christ had only just got going, and it was going to get an awful lot worse over nearly two thousand years, even until this very day. The nations are yet to receive God's final judgment, as described in the book of the Revelation.

In both cases, all the nations involved, and all the individuals comprising them, cannot claim that God never warned them, or didn't give them enough time to get right before God.

However, the question switches from the Amorite nation to individuals in it. Likewise, it switches from "the wicked" in general, to individuals specifically. It takes "vessels made for dishonour" to speak of individuals. Yes, individuals made up the nation of Amon; yes, "the wicked" requires many individuals to make up the collective; yes, "vessels unto dishonour" in Romans 9:21 involves individuals. But note that in Romans 9 that although Pharaoh is singled out in particular, the whole nation of Egypt back then was crushed under God's hand of judgment. And it adds in verses 22 to 24:

"What if God, willing to shew his wrath, and to make his power known, endured with much long-suffering the vessels of wrath fitted to destruction: And that he might make known the riches of his glory on the vessels of mercy, which he had afore prepared unto glory, even us, whom he hath called, not of the Jews only, but also of the Gentiles?" Romans 9:22-24 A.V.

Then comes the wonder of it all, in the next verses, where Paul quotes from the prophets Hosea and Isaiah, to show God's mercy in calling people who were not his people, "my people", and those not beloved, "beloved", and those not his people, "children of the living God". Consider this promise of God:

"...a remnant shall be saved, for he will finish the work, and cut it short in righteousness, because a short work will the Lord make upon the earth." Romans 9:27-28 A.V.

The Bible shows us how God consistently deals with nations, exercising his sovereignty over them, and - at the end - judging all nations. Yet it also shows his care for individuals, granting salvation and forgiveness to those who humbly bow before him and who put faith in his means of salvation. Never forget, though, that although God knows the end from the beginning, individuals are never forced to sin against him. He knows what they will do, yet they can repent and be forgiven. For those who utterly harden their hearts against him, they become so brittle that their end is according to righteous judgment. As Isaiah said when predicting God's judgment against the nation of Israel back then:

"But the Lord of hosts shall be exalted in judgment, and God that is holy shall be sanctified in righteousness... Therefore as the fire devoureth the stubble, and the flame consumeth the chaff, so their root shall be as rottenness, and their blossom shall go up as dust: because they have cast away the law of the Lord of hosts, and despised the word of the Holy One of Israel. Therefore is the anger of the Lord kindled against his people..." Isaiah 5:24-25 A.V.

Yet the Lord saved a remnant. He knows when the full measure of sin is reached with nations, and he knows when individual sinners repent and turn in faith to him. The whole Bible repeats those lessons over and over again. That is a point to look out for when struggling with the massive issue of God's sovereignty over nations, and our individual sin.