Let's say we lived in a city -- let's call it "New Jerusalem." It's a beautiful city which has been built up over 2000 years. We love our city and are devoted to it to the point that we would sacrifice our lives for it.
But at this particular point of history, the city is besieged on all sides. It has suffered other sieges over the course of its long history, but this is perhaps the most dangerous situation yet. Enemies attack it relentlessly from without. Even worse, it is known that there are numerous traitors who are undermining it from within. The city has suffered devastating casualties with the loss of tens of thousands of officers and millions of citizens.
Do we serve our city by ignoring the problems? Is it true loyalty to pretend that nothing is wrong? Will we save our city from destruction by happy talk divorced from reality?
Let's say that the citizens of the city believe that God has promised that the city will never be entirely destroyed. Do we fail for that reason to combat the enemies, both external and internal. Do we have any less obligation to fight to the death? Or is God's promise perhaps contingent on OUR faithfulness?
The citizens of "New Jerusalem" may delight in their city, but they are called to be "militant," and they fail in their duty if they shirk the necessary tasks when times are at their bleakest.