The division ELCA vs NALC is not a matter of dialog never engaged in but a story of dialog and decision over 20 years and ending in the conclusion that we did not hold enough in common. It is not what we hold in common that is the trouble.
I am not suggesting that Christians should not dialogue about their disagreements. In fact, to the contrary. I am a strong proponent of dialogue. I am talking about how we shape the conversation.
Please consider two different approaches to buying a new car. What kind of relationship develops between the buyer/salesman when the negotiation begins with a buyer trying to low ball and dealership that is trying to sell the car for sticker price ++. That is how I think Christians/Lutherans tend to approach their disagreements. As an alternative, what would the conversation look like if the buyer says, "I would like to buy this car at a fair price. Fair means you make you margin and I get a bargain. How do we determine the dollar amount that corresponds with fair". That is the kind of conversation that I am advocating.
And again, what gives you the conviction that God does not want the NALC vs ELCA division?
Jesus' high priestly prayer.
I have every confidence that God will use that division, just as God will use the ACELC/Jesus First division in LCMS, to accomplish His purpose. But, God's intention is for us to be one, just as Jesus and the Father are one. In Baptism, God has claimed each of us as His child. God has called each of us into a unique and loving relationship with Him and, empowered by God's love, we are called to live that same relationship with one another.
For that matter, maybe "dialog" is merely the sinners' attempt to pool their sin and ignorance rather than repenting.
If by "dialog" you mean talking at one another (rather than talking with one another), I agree.
Your objection to division seems to be based more in personal preference. One could dismiss that by saying: "So what," and be perfectly justified in doing so.
Without question, it is my personal preference. Out of the same mouths are proceeding blessings for those with whom we agree and curses for those with whom we disagree. That ought not to be so! Are divisions are hurtful. Worse, our divisions, or, at least our poor behavior in dealing with divisions, bear false witness to the Gospel. So, I think it is more important than "so what".