And here is why I am confused. Most Protestant churches don’t teach this.
You are correct, many do not teach the truth on this matter.
If people are divorced, then they are divorced and the marriage is dissolved. Why is it a sin then?
Because sin is not dependent upon what people believe. Sin is a reality. God’s law is eternal and universal. Something either transgresses God’s law or it doesn’t.
God holds all people accountable for what they can know through human reason. He additionally holds Christians responsible for what has been revealed through Divine Revelation.
In your example, the marriage is
not dissolved. That is the reality. Subjectively these people are in error in believing they can contract another marriage. Whether or not they are in a state of
sin depends upon whether or not they have full knowledge and free will-- we cannot judge whether they are sinning. We can judge the rightness or wrongess of their action based on the objective moral criteria given by Christ.
Do all Protestants have to visit a Catholic church even though they have absolutely no affiliation with the Catholic church to dissolve their marriage? I really don’t understand why it matters.
The Catholic Church cannot dissolve any valid, sacramental marriage-- Catholic or non-Catholic.
If you mean “declare null” that is not the same thing as “dissolve.”
Let’s straighten that out before we go further.
Where is this in the Bible?
Christ taught that Moses had erred in allowing divorce and allowing remarriage. Christ states that no man can separate what God has joined.
I know it says that unfaithfulness is grounds for divorce.
It does not state that a divorced person can remarry. The passage in Matthew indicates that there may be times when a marriage is unlawful-- i.e. null from the beginning. This is often mistranslated into English as “unfaithfulness.”
Also, in John, it says if you confess your sins to God you will be forgiven - for those who see divorce as a sin.
The Church does not see civil divorce as a sin. There are legitimate reasons that one may need to legally separate from their spouse to protect them or their children, physically, mentally, financially, etc.
Adultery is a sin, and adultery is committed whenever a person who is already married (whether civilly divorced or not) attempts to marry another while their spouse is still living.
Confession of any sin on the part of the person for the root causes of a divorce certainly should be confessed. However, forgiveness for whatever part they played in the breakdown of their marriag (if any) does not give them the ability to marry another.
What God has joined, no man can separate.
But where does it say that the marriage has to be absolved through the Catholic church?
You have some wrong ideas. The Church does not teach that marriage can be dissolved (I believe that’s what you meant when you wrote absolved).
I am truly concerned about this.
In what way?