I read from the following link
Lutherans believe that Christ died for the sins of all people and that God wants all people to be saved (see, for example John 3:16, 1 John 2:2, 1 Timothy 2:4-6). However, not all people are saved. Why? Lutherans would say that we don't know why. That is, if my first sentence of this paragraph is true, then the logical question is "why is not everyone saved?" The Lutheran answer is, "we don't know, because God doesn't tell us."
I propose an analogy something like this :
There are 100 persons is about to drown in the sea. All of them will be surely die if there isn't any salvation team, but still some of them (70 persons) are trying to rescue themselves.
SAR team is coming and throw a life vest for all those 100 persons. Too bad, the one who is trying to rescue themselves still think that they can rescue/save themselves. So, the 70 persons abandon their life vest. The 30 persons grab and put their life jacket.
Q : who are saved (reach the land) at the end ? A : the 30 persons.
Conclusion, even the SAR team is there for all those 100 persons - because the "stubbornness" of some of them, so at the end not everyone is saved. (the bold here is the answer of the bold question from the Lutherans above).
My analogy is involving Freewill. I don't know if Lutheran teaching believes on Freewill or not. That's why I ask here.
The analogy can not be applied to the past. If say in the analogy there are some already dead drowned, then the SAR team coming is too late for the one who already dead :)