At some point Lehi gave a commandment to his children that does not get mentioned until his son Jacob added his own record. Jacob wrote: “they have not forgotten the commandment of the Lord which was given unto our father, that they should have save it were one wife, and concubines they should have none, and there should not be whoredoms committed among them.” RE Jacob 2:11.
Jacob mentions this inside a message about the ultimate Nephite fate. He reports the Lamanites obeyed that commandment given to Lehi, but the Nephites were disobedient, and instead recklessly practiced permissive behavior described as “whoredoms” that had “broken the hearts of your tender wives and lost the confidence of your children.” Id., @ 9.
It is because of the Nephite violation of marital fidelity and rebellion against greater light that the Nephites were to ultimately be destroyed while the Lamanites would suffer no such destruction. “Wherefore, because of this observance in keeping this commandment, the Lord God will not destroy them, but will be merciful unto them, and one day they shall become a blessed people. Behold, their husbands love their wives, and their wives love their husbands, and their husbands and their wives love their children.” Id., @ 11. This Lamanite virtue merited God’s mercy for all generations that would follow.
Now think about this contrast. The Nephites had prophets, scripture, a correct tradition, ongoing revelation, visitations by angels, and even were visited by the Lord. But they had no promise of being preserved. On the other hand, because of their obedience to the commandment about marriage, and spouses loved one another, they were promised to be preserved while the Nephites were condemned to destruction. The Nephites had “greater light” and it served only to condemn them because they rebelled against it.
That is a remarkable thing to me. And it reinforces the significance (the eternal significance) of how we behave in our marriages.