Why is divorce unchristian?

In marriage, spouses leave their parents and unite with each other (Mark 10:7) to become one flesh (Gen.2: 24). Because, it is a covenant of love, and God is love (1 John4:8), it is God who seals the marriage covenant; and no one can separate what God has joined together (Matt 19:6). In divorce, therefore, this covenant is not broken; it is rejected. Therefore, remarriage after divorce is adultery (Luke 16:18). Furthermore, since God seals this covenant, divorce is rejection of God. God, therefore, hates divorce (Malachi 2:16) and is not pleased with the offerings of those who divorce their spouse (Malachi 2: 13-14). Jesus tells us that before making offering to God, we must reconcile with those with whom we have grievances (Matt. 5: 23-24). Therefore, a divorced person must first reconcile with his/her spouse before making an offering to the Lord. Furthermore, even if there is unfaithfulness a person must still stay faith to his/her spouse, just as God His faithful to us even when we reject Him (Hosea 3:1).

Divorce is absolutely prohibited in the Gospels (Mk 10:11-12, Luke 6:18; Matthew 5: 31-32). In Matthew’s gospel there appears to be an exception. The exception in the Greek text is porneia (which means incest or fornication), and not moiceia (which means adultery). In the Mosaic Law (Lv 18:6-18) certain types of marriages between close relatives were unlawful, because, they were regarded as incest (porneia). Certain rabbis, however, allowed gentile converts to Judaism to remain in such marriages. The exemption in Matthew’s gospel is against such permissiveness for gentile converts to Christianity. Fornication is another meaning for porneia. Therefore, this exception also applies to couples who fornicate by living together without a lawful marriage (also known as common law marriages).

In Christ

I would also like to add a couple things to this. We also are to forgive everything that is done to us so that our Father will forgive us. IF we forgive everything that a spouse does to us- AND we stop being selfish and thinking about ourselves, but we put THEIR interestes and good first then we ourselves will have no justification for divorce. ( of course if the other spouse is doing the divorce all the spouse can do is try to reconcile and pray and stand in faith for the Lord to restore them, as we cannot make any man do anything only God can) But Love forgives and love believes all things and trusts all things and DOES NOT SEEK ITS OWN which is where most divorce comes from. If we are TRULY dying daily to self, then we will have no room for flesh to take a stand and say the popular justifications for divorce to such as " i dont love him or her anymore" " i just need to be happy" " i shouldnt have to take this" " life is too short"(indeed it will be for you if you do not heed the Lord!).

Another reason people get into divorce is that they want to look to their spouse and say he or she is not being what God says they should be! WE SHOULD NOT DO THIS! we should however look to what God says WE are to be in that marriage and we should conform to that NO MATTER what our spouse is doing or how unchristlike they are being or how they treat us etc..

How terrible a thing, if we are willing to be persecuted by the world for Christ, but if we do not love our spouse enough to be persecuted by them! you do know oh wife if you will save your husband! and vice versa. We should love our spouse so much that we would be persecuted daily by them, and be thankful that we are the ones to be there to be persecuted, that no matter how many years that happens, if one day they are saved, or repent or get closer to the Lord because of our example, each day was worth it AND each day was perfect for us because it helped us to die to self and partake in the sufferings of Christ.

Its a bit more than that, but agreed.

Since God is love (1 John4:8), it is a covenant of God.

This seems to be a non-sequitor argument.

No one therefore, can put aside the covenant (Matt 19:6).

This again is non-sequitor.

Divorce therefore, goes directly against God;

And this as well.
These steps you are setting up do not logically follow.
Just because God is love it does not follow that divorce is 'against' God.
He Himself gave a writ of divorcement, then later ended that covenant.
It is the SIN that causes divorcement is what is 'against' God, the divorce itself is not necessarily that sin.

and those who remarry after divorce commit adultery (Luke 16:18).

This is only partial evidence. Adultery is not always committed upon remarriage based on Christs own words.
Also, the Present Indicative form of 'committeth adultery' used to render Christs words from the Hebrew or Aramaic do not show any 'ongoing' adultery but instead shows only that the sin is happening in the present at the time of those acts themselves.

God is therefore, not pleased with the offering of those who divorce their spouse (Malachi 2: 13-14).

Most of what you presented so far was non-sequitor to begin with, as is the case with this assertion as well.

God always stays faithful to His covenant with us.

Correct.
He is 'faithful' to reward and He is faithful to condemn where apostasy is present.
This is the case in both the old and the new covenants as proven by Hebrews 6 and 10, among others.

When we were unfaithful to Him, He brought us healing by sacrificing His own life.

This is quite incomplete.
Who is it that Christs blood will save ? Everyone or those who 'endure till the end" ?
Christ died for sins, but only those who are faithful to Him/God will have His blood applied to their sins. Those who apostate cannot be brought back to repentance. Those who reject entirely are never sanctified by His blood to begin with.
So there is a bit more to the picture here that what was presented.

As believers, we are called to love our spouse just as Christ loves us (Eph 5:25).

That is correct.

The Lord told Hosea (Hosea 3:1), "Go, show your love to your wife again, though she is loved by another and is an adulteress.
Love her as the Lord loves the Israelites, though they turn to other gods and love the sacred raisin cakes." We therefore, have to be faithful to our covenant with our spouse, even when there is unfaithfulness and hurt; and bring healing to our spouse by our prayers, sacrifices and support.

Hosea was a prophet who unique life was used by God to show what Israel had put Him thru.
Hosea situation is not comparable to any other marriage in existence in any time.
Only if a person was literally commanded to marry a harlot would Hosea be even remotely similar to ANY other marriage.
Hosea is not evidence either for or against any argument in the MDR issue. It is entirely irrelevant.

Divorce is absolutely prohibited by the Gospels (Mk 10:11-12, Luke 6:18; Matthew 5: 31-32).

Completely inaccurate.
Frivolous (for EVERY cause) divorce is the context entirely with the Jews and why Jesus taught about it so much. This frivolous divorcement to marry another is what Christ is condemning.

In Matthew’s gospel the exception is for unlawful marriages.

Erroneous.
Porneia is any and all illicit sex of any person either married or unmarried.
If the married person partakes of this illicit sex, it is also the marriage specific 'crime' of adultery.

The exception in the Greek text is porneia (which means incest or fornication), and not moiceia (which means adultery).

Exactly.
If Jesus had said 'except for adultery' He literally would have been limiting the grounds for divorce to ONLY illicit sexual activity post marriage.
In using porneia to render our Lords words into greek Matthew shows that Christ was also including things such as premarital sex and bestiality...ANY sexual perversion.
That is the reason porneia was used, because it covers sexual perversions that 'adultery' would not.

The exception is for marriages between close relatives, which according to Mosaic Law (Lv 18:6-18) were unlawful, because, they were considered as incest.

Absolutely incorrect.
There are at least two entire letters (Ephesians and Colossians) where sexual immorality is forbidden as a WHOLE and in neither of those letters is any form of adultery used.
If what you were saying were true, then those letters would ONLY be prohibiting incest. This also includes Acts 15, btw, and the instruction to the WHOLE gentile church.
Do you realize just how many OTHER acts of sexual immorality there are besides incest ?
Do we claim that in these other cases where ONLY porneia is used that ONLY incest is being forbidden ?

Porneia is is ALL harlotry/sexual immorality of ANY kind by any person, married or unmarried.
Jesus picked just the right word for His exception. He did not restrict His exception to only adultery post marriage.