I have some serious reconsiderations now on this topic. Ideally we should pray and have peace. But God has not forced peace, wholesome holy shalom on the hearts and minds of men. God is not coercive even when men wish to do evil. God allows for us to choose, and the freedom we choose will define our everlasting souls.
The Apostle Paul wrote that we should "be at peace with all men as much as is possible." When peace is IMPOSSIBLE, as it is fast becoming today in Europe and the USA, we will have to choose wisely how to respond to those who disturb the peace with suicide vests, guns of all kinds, with jetliners and now Mack trucks. Or we will have to simply accept the consequences of being ruled by those who will take peace from us.
Ideally, God can use the armies and constabularies of the nations to keep those who wish true peace from all harm. Will this ideal as it has been experienced much in the USA continue? We MUST pray. Should we , should I take up weapons to defend myself, my family, my neighbor and my countrymen? Why don't you tell me?
Here is what I wrote on March 11 last year:
Christians don't go to war with swords and guns. Jesus came to fulfill the law and the prophets and he did it how? By defending the lost sheep of the House of Israel? No.