There are extreme circumstances that cause divorce and remarriage, however in our day most divorces and remarriages are not based on these extremes. Divorce is being used as an out when there are no biblical reasons.
Luke 16:18
“Everyone who divorces his wife and marries another commits adultery, and he who marries a woman divorced from her husband commits adultery."
1 Corinthians 7:10-11
"To the married I give this charge (not I, but the Lord): the wife should not separate from her husband (but if she does, she should remain unmarried or else be reconciled to her husband), and the husband should not divorce his wife."
It is clear from God's word that remarriage is adultery, no one can separate what God has joined. It is a spiritual union that God creates in us when we marry.
Matthew 19:6
"So they are no longer two but one flesh. What therefore God has joined together, let not man separate.”
What God has joined no man can unjoin, its permanent until death.
Our culture has been taught that there is an "exception clause" for divorce, that being adultery. This is not biblical. When God said "except for fornication" in the book of Matthew, He was describing the betrothal or engagement period of the Jews. When a young person was betrothed in the Jewish culture it was nearly as permanent as the marriage. There was only one exception during the betrothal period that allowed for a divorce from the engagement. That exception was when one party in the betrothal had been unfaithful, not during the marriage but during the engagement.
This is why the word "fornication" was used instead of the word adultery. Notice in the other three gospels there is no such provision for divorce, because Matthew was written to the Jews who had the provision for divorce during the engagement.
The other gospels were written to the Gentiles who had no such custom of a binding engagement. The Jews however had to obtain a divorce from the engagement to dissolve the covenant made by the parents for the young people.
This is one more thing that American Christians have misunderstood because of the English language that does not understand the culture of the Jews in Biblical times.
Life is full of heartbreak in marriages, but that does not mean that these heartbreaks cannot be worked out over time. In my marriage I can tell you that we had many problems in the beginning. We were not born again yet, then I became born again before my husband spending about ten years in a marriage with one saved and the other not. It was difficult because we were not of one mind.
Because even in our unsaved state we didn't believe in divorce we stuck it out. Then I became born again, things got even harder, but over time my husband became born again and the kinks of our marriage began to iron out as we began to grow closer, more of one mind. Today we have a wonderful marriage, but it took years of commitment, confess and forgiveness to achieve this.
Sadly too many people bail out of marriage before God has a chance to work out the kinks, discipline the sinners and cleanse. Bailing out of our trials is what Americans do.
Instead of admitting our sin and facing the consequences of immorality a baby is killed. The consequences for sin of the parents is placed on the baby a death sentence so the parents never have to work out their problems, problems that they made for themselves. This is true in marriage too!
Americans no longer see the value of suffering for Christ, whether in marriage or the consequences of sin in other ways.
Marriage is a covenant between two people and God. That covenant begins at the altar when the promise is made. The same standard we expect for believers is expected by God for the unbelievers. Unbelievers are accountable to God for their own broken promises as much as any believer. The difference is that the believer is disciplined for their sin and the unbeliever is on their way to hell because they do not have an advocate with the Father as believers do.
Unbelievers are going to hell to pay for their own sin and believers are not going to hell because Jesus Christ paid the price for theirs. However, God allows the consequences of life to discipline the unbeliever, but actively disciplines the believer for theirs to bring them back to obedience.
This is a hard truth, even the apostles said it was hard because most cannot accept that they might be in a marriage that is difficult for the rest of their lives. Let us remember that we chose our spouse, who are we to abandon them at their worst moments.
So many people don't seem to look to God to hope for a change in ourselves and in our spouses. We just give up and abandon the marriage at its most difficult point.
Our culture does not seek to "wait it out" praying and hoping for better days, we just bail out, blame others and get a new spouse. The problem with this is that every time someone gets a new one they take themselves with them.
Do we really want a spouse that will bail when things are tough? People do change, sometimes not but if we trust Christ, carry on in faith, often the person we thought was so terrible changes and becomes a new creation. I have seen it many times in my life.
It is one thing to remove ourselves from someone who is a narcissist that is not a spouse, its quite another to walk away from our covenant spouse who became one with us for life. God forbids it.
No one who is born again will lose their salvation for remarriage but they will certainly have consequences that may last a lifetime.
Lets not encourage what God says He hates!
So many marriages miss the blessing from hanging in there until God does a work. They bail out to save their own lives before God has a chance to bring healing. Sometimes that healing takes years, God's timing is not ours and His purposes are not ours.