Be very careful, then, how you live (Eph. 5:15), put on the full armor of God (Eph. 6:11), prepare your minds for action (1 Peter 1:13), make every effort (2 Peter 1:5), be self-controlled and alert (1 Peter 5:8). These are battle cries, and Scripture is full of them. But unlike our old conception of warfare, where battle lines are clear and the times of battle can almost be predicted, this is modern warfare in which you are not always sure where the enemy lurks. It is guerilla warfare. There are strategically placed snipers. You let down your guard for a moment and the village you thought was safe suddenly opens fire on you.
Edward Welch