Marriage is a central theme of the Bible. God began marriage with Adam and Eve in the Garden of Eden. God’s law for marriage is that a man and woman be joined by a vow of loyalty so long as both partners are alive.

Under the Law of Moses, many rules and regulations about marriage were part of the Law. Marriage of near kin was forbidden, and Moses gave permission for divorce that was not part of God’s will for marriage from the beginning. The Law decreed that sexual immorality be punished by stoning to death, but because of the hardness of the hearts of Israel, Moses permitted them to write a bill of divorce and put their wives away because of sexual immorality. The person put away, divorced because of sexual immorality, was permitted to marry again, but not permitted to return to their first husband after being married to someone else.

The way that God dealt with marriage issues under the Law of Moses teaches us something about God’s will for marriage. God made provision for man’s failures. He often forgave marriage sins and used weak people to accomplish His purposes. God never overlooks sin, and always requires an accounting for sin, but by His love has paid the account in full through Jesus Christ for all who believe in Him. We should expect God’s grace and mercy to extend to penitent past violators of God’s marriage law today, just as He has always extended His grace and mercy to those who love and serve Him.

Traditional teaching on marriage, divorce, and remarriage concludes that God does not recognize or count marriages made against His will as being marriages in fact. Therefore it is concluded that people who married against the will of God are not really married, but living in adultery.

A study of all the Bible teaches about marriage will convince us that the traditional "living in adultery" understanding of what Jesus taught in Mat 19 is not supported by the general teaching of the Bible. What Jesus said in Mat 19 agrees with the Law and the Prophets. Jesus did not give a new marriage law. Jesus taught about the existing marriage law that was given in the beginning when Adam and Eve were joined as husband and wife in the presence of God.

God’s will for marriage is that one man be married to one woman for as long as they both live. God wants that relationship to be unselfish, with each person concerned for the needs of the other person. They are to be one flesh, and to leave father and mother and cleave to each other.

God commanded that mankind should not destroy this blessed relationship. The fact that God forbade man to destroy marriage surely implies that man can destroy marriage. The Bible is full of stories of how men and women sinned regarding God’s marriage law. Because of the hardness of the hearts of Israel, in that they did not want to obey God’s marriage law, Moses permitted them to divorce their wives because of sexual immorality, and to give them a bill of divorce so that they could go and marry someone else, Deut 24:1-4. This was not God’s will from the beginning, because He wanted men and women to be faithful to each other as husband and wife until one partner died.

Yet God described as divorce His putting away, because of idolatry, of the ten northern tribes of Israel, Jer 3:8. This shows clearly that the sin of unfaithfulness justifies divorce. Divorce was not God’s plan from the beginning, but some sins justify divorce in some circumstances.

Jesus said to Israelites living under the Law of Moses that the only way a man could, without sin, divorce his wife and remarry (without the sin of adultery) was if the wife was guilty of sexual immorality, Mat 19:9. This one exclusion given to God’s covenant people living under the Law of Moses does not necessarily apply to all people and all situations. When we study the Bible carefully, we find that Ezra commanded Israelites who were married to foreign wives to get rid of those wives, Ezra 10:10-11. Paul showed that in a mixed marriage between believer and unbeliever, if the unbelieving partner departed, there is no requirement to continue the marriage relationship, 1 Cor 7:12-16. Paul indicated that Jesus did not speak about this situation of marriage of a believer to an unbeliever, 1 Cor 7:12-13. Thus we conclude that the context of Jesus’ instruction in Mat 19:9 is to a believer married to a believer, 1 Cor 7:10-11.

We know that the Israelites were not responsible for enforcing God’s marriage law on the people of other nations. Paul taught that Christians are not responsible for policing the morals of the unbelievers, 1 Cor 5:9-13. But when we study Mat 19:9 in light of what Paul said in 1 Cor 7:10-11, it becomes clear that the church is responsible for enforcing God’s marriage law within the church. Willful sin is very dangerous. When people plan to sin, knowing that it is against God’s will, it will be extremely difficult for them to ever repent, Heb 10:26-31. Divorce and remarriage between Christians cannot take place without sin: either the sin of unfaithfulness against the marriage by sexual immorality, or the sin of unjust divorce and remarriage against the will of God, which is called adultery.

Four wrong assumptions lead to misunderstanding how we must respond to violations of God’s marriage law.

The bible is full of history of marriages made against the will of God that were recognized by God as marriages in fact. Every marriage of more than one wife was against God's will, but God recognized those marriages. Men and women marry when they agree to live together as husband and wife. They can marry according to God's will or against his will, but it is a marriage either way.

Jesus said, "What God has joined together, let not man put asunder." God does not command against that which cannot be done. When Jesus said, "let not man put asunder," it implies that man can put asunder. Man can and does divorce and marry against the will of God.

The scriptures show clearly that adultery has another meaning of unfaithfulness or apostasy. The way a word is used in context always determines the meaning intended. Modern meanings of English words cannot be used as authority for the original meaning of the word in Hebrew or Greek (the modern English meaning of baptism includes sprinkling of infants).

The Old Testament word translated adultery meant having sex with the wife of another man.

The New Testament word translated adultery refers to (male) paramour as the root meaning.
NT:3432
moichos (moy-khos'); perhaps a primary word; a (male) paramour; figuratively, apostate:

NT:3431
moicheuo (moy-khyoo'-o); from NT:3432; to commit adultery:
(Biblesoft's New Exhaustive Strong's Numbers and Concordance with Expanded Greek-Hebrew Dictionary. Copyright (c) 1994, Biblesoft and International Bible Translators, Inc.)

Both words have apostasy as one of the meanings. Jesus said that a man who lusts for a woman has committed adultery in his mind. A mind that forsakes faithfulness and longs to be connected with another is described by Jesus as committing adultery, Mt 5:28. How can we conclude that adultery can only mean having sexual intercourse with the wife or husband of another person?

In Mat 19 the context forces us to see that unjust divorce and remarriage equals adultery. The sin of apostasy against the wife and against God's will is clearly indicated. When we put all the emphasis on the physical act of sexual intercourse, we miss recognizing what is the real sin under consideration. Jesus did not say that a man who married a woman against the will of God continues to live in adultery so long as he is married to that woman. There is no place in the Bible where we can find the phrase "living in adultery." We should be able to describe things taught in the Bible with the same language the Holy Spirit used to teach the thing.

While the penalty for violating marriage law was different under the Law of Moses and in the new covenant, the marriage law itself was unchanged, as Jesus clearly showed when he went back to Adam and Eve in the garden to explain how the marriage law has always been.

Jesus in Mat 19 was answering a question pertaining to marriage under the Law of Moses. He said nothing to indicate that he was talking only about the future circumstance in his kingdom, but He answered a question that was highly debated in the two rabbinical schools of His time. The school of Shammai held that divorce was only permissible for the cause of sexual immorality. The school of Hillel held that a man could divorce his wife if she fell into disfavor for any reason. The Pharisees were trying to cause problems for Jesus by getting him to speak on an issue that was bound to offend some of the audience. Jesus went back to the beginning and showed what God's will for marriage has always been.

Nothing Jesus said in Mat 19 differs in any way from what the Law of Moses taught about marriage. When Jesus said that from the beginning it was not God's will for divorce to take place, that does not mean that divorce is not called for in some circumstances. God divorced Israel (ten northern tribes) because of spiritual adultery. Jer 3:8 - "I gave faithless Israel her certificate of divorce and sent her away because of all her adulteries." NIV

Deut 24:1-4 directly refutes the idea that the guilty party in a divorce because of sexual immorality is not permitted to marry. Jesus said nothing about the right of the guilty party to remarry, but Deut 24:1-4 shows that the guilty party was permitted to remarry.

Also, there was and is another reason for ending a marriage relationship allowed in special circumstances; that of a believer married to an unbeliever who is unwilling to live peacefully. Ezra demanded that Israel send away their pagan wives who were involved in trying to prevent the restoration of Jerusalem and the temple worship. There is no record that men who sent out their foreign wives were forbidden to marry again.

Paul states clearly that a wife is not bound to an unbelieving husband if he chooses to leave her. Jesus did not address this issue at all in Mat 19, as Paul shows with these words in 1 Cor 7:12: "To the rest I say this (I, not the Lord)." NIV

The Bible does not teach that the person guilty of violating God’s marriage law by unjust divorce and remarriage must again divorce in order to repent, and then remain unmarried. The person divorced for the cause of sexual immorality was permitted to remarry, according to Deut 24:1-4. Nowhere in the scripture is the person divorced for just cause commanded not to marry. If the person divorced for just cause was permitted to remarry, why should we think that the person unjustly divorced would not have the right to marry once the preserving of the first marriage is no longer possible? When a Christian refuses to honor God’s marriage law by being faithful to their marriage partner, they may well be classed as an unbeliever. Those who refuse to honor and obey Jesus are not truly believers. See 1 Cor. Chapter 5, 2 Cor. 6:15, and 1 Tim 5:8. A Christian is not bound to continue a marriage where the partner is an unbeliever and unwilling to live with him or her. The scriptures teach that a former Christian who rebels against God and returns to slavery to the world is an unbeliever, 2 Pet 2:20-22

The problem in understanding about marriage, divorce, and remarriage is not with what God wants; it is about how violation of God’s marriage law can be repented and forgiven. The Bible does not teach that a subsequent marriage (after unlawful divorce) must be destroyed in order for repentance to take place. Some teach that the first marriage is still in effect, but Jeremiah said that returning to the partner of the first marriage after divorce and remarriage would pollute the land, Jer 3:1. Restoration of the first marriage after divorce was specifically forbidden by the Law of Moses, Deut 24:1-4. Therefore restoration of the destroyed marriage is not a requirement of repentance. Repentance requires godly sorrow that produces a change of heart, a heart that desires to please God in all things, including remaining faithful to our legal wife at the time of our repentance.

God does recognize marriage vows that are made against His will. God’s approval is not needed for a marriage to be a marriage in fact. Men and women can marry according to the will of God, or against the will of God, and it is still a marriage. The marriage of Israel to four wives is testimony to this fact.

When one repents of past sins, he/she comes to God as one is, in whatever legal relationships are present, and determines to live faithful to Jesus including keeping lawful vows. True repentance will require that one does not again commit sin against a marriage partner, and against God.

It seems strange that some, under the law of the spirit of life in Jesus Christ, seem to have more harsh attitudes about sin and repentance than God demonstrated under the Law of Moses, the Law of Sin and Death. Perhaps the harsh attitudes result from thinking that we must be justified by keeping rules, and therefore all the emphasis is on keeping what are believed to be commandments. Often the commandments being enforced are actually opinions derived by human logic. We would do better to trust the righteousness that is in Jesus Christ, and endeavor to please Him in all things.

We must avoid using unbiblical study methods in our approach to study of the Bible. Who believes what, or how smart or well educated the teacher, is not the source of Bible authority. The basic teaching of Scripture, considering everything the Bible has to say on the subject, is Bible authority. Many highly educated men have promoted false ideas and divided the church ever since the first century. Logical arguments based on wrong assumptions lead to false conclusions. The qualified student of the scriptures will depend on a broad and general understanding of a Bible topic as revealed in the complete teaching of the Holy Scriptures. Truth has nothing to fear from examination.