Marriage is a Picture of Salvation

One of the misunderstandings about the "exception clause" in the book of Matthew,  is that it was referring to marriage, it is not. In the Jewish custom "betrothal" or as we say engagement, is nearly as binding as the marriage with one exception. 

The betrothed, (engaged) couple must provide a certificate of divorce from an engagement if one of the parties was found to be unfaithful. 

In the KJV of the Bible the words used in Mathew "except for fornication" is properly translated as being before marriage. God was speaking to the Jewish people according to their customs for divorcing from an engagement. Notice that God never has this exception in the other gospels, its because he was speaking to Gentiles who didn't have a custom of divorcing from an engagement. 

There is no exception for adultery in marriage in God's Word. In fact, God clearly said He set aside Israel but will be reconciled to her during the tribulation. The marriage of a man to a woman is a picture of Christ and His church. Nothing can dissolve the union of Christ to His believers. 

God said in the Word, "let no man put asunder" meaning, "no man can put asunder what God has joined. It does not matter which sin anyone commits they cannot be severed from the marriage. 

When God makes someone a new creation they cannot go back and be the old again, the old has passed away.. When a man and woman marry for the first time God makes them one, this is a work of God that cannot be severed by any man, not even the adulterous person. No one can undo what God has done. 

There is no sin greater than another sin that cannot be forgiven or that severs the relationship of a oneness union. All sins can be forgiven. Also notice there is nowhere in the word that commands someone to divorce, this is because divorce is not possible. 

Christ died for us while we were yet sinners, that is every kind of sin possible was included, He would never give a command that demonstrates a lack of forgiveness or a severing of what He did. 

2 Timothy 2:13 "13 if we are faithless, he remains faithful—for he cannot deny himself." 

Christ said that if we so much as lust after someone its the same as committing the sin of adultery. So do we divorce because someone had a lustful thought? No, there is no sin that can sever or break the marriage oneness that Christ did in the marriage. 

Also, this is for unsaved people too, otherwise, they would not be dead in their trespasses and sins. The same sin we repented of to become born again is the same sin the unsaved remain in before they are born again.. 

Let's remember too that nothing God does can be undone by man. If we love Him we "will" follow His commands, not perfectly but when we sin we hate it and confess to be cleansed. 1 John 1:9 

We also have an advocate with the Father because we belong to Christ, non-believers do not have an advocate. 

1 John 2:1 "My little children, these things write I unto you, that ye sin not. And if any man sin, we have an advocate with the Father, Jesus Christ the righteous." 

God still loves us when we sin and we remain saved, a picture of us and our spouses.