When we hear the term “spiritual warfare” we might think of casting out demons and/or praying for lost loved ones to be converted. That’s certainly part of the story, but in many respects it’s a very small part.
Each of us is in an ongoing spiritual battle every moment of our lives; if we’re unaware of this fact, perhaps we’re asleep in captivity, or worse — on the wrong side.
We’re in this battle 24X7 because Satan never rests or gives up; he never backs off and gives us a break. (1Pe 5:8) Whenever we let our guard down, he’s right there to take advantage (2Co 2:11): to steal, kill and destroy. (Jn 10:10) Whenever we make a little more room for him, he takes more ground and fights to hold on to it. (Ep 4:27)
If we’re ignorant of the struggle, then we simply aren’t in the fight. This can only mean one of two things: either we’ve been taken prisoner and Satan has us right where he wants us (2Ti 2:25-26), or we’re in league with the enemy and serving him. (Ep 2:2)
This battle can be described very simply: Satan lies to us to get us to sin, to violate God’s Law. (1Jn 3:4) Every time we believe him, we give him more power in our lives. (Jn 10:34) To engage him in battle we [1] identify the lies [2] believe the truth (repent) and [3] live in truth with our whole mind, heart and soul. (Jn 8:31-32) Every dimension of spiritual conflict of any concern to us can be related in these terms.
This war is not one of our choosing; Satan chooses when and how to fight us; we can either defend ourselves or give in to him and let him defeat us. There aren’t any other choices here.

Seeing we’re in such a battle, we should learn to think and act like soldiers who aim to win. A warrior disciplines himself to endure hardness and difficulty (2Ti 2:2); he doesn’t entangle and distract himself with worldly affairs; he’s focused on the mission, ready at a moment’s notice to engage the enemy. (3)
A good soldier keeps his weapon close and becomes proficient with it, always training and improving. He studies to understand his enemy (2Co 2:11) and learns proper military strategy from those who’ve succeeded in combat. He also learns from his own mistakes and failures, integrating his own practical experience. When he fails in battle, he doesn’t resign himself to failure: he doesn’t quit. He picks himself back up, studies and trains to correct his mistakes, knowing he is destined to overcome. (1Jn 5:4)