I have many thoughts on the subject of spiritual warfare. Thoughts that are broken up and on going, hence this second part.
There seems to be both disdain and an over-zealousness towards the thought that there can be demonic influence towards the world, especialy towards the christian as an individual. I have no problem admitting that demons have windows of opportunity in which they can try to sway me off course in my pursuit of God. I do believe that Satan has the power to effect earth as a whole as well as our current and local situation (as seen in the book of Job). I also believe that most of the time when we suffer in some way it's usually just because that's the way it is. We live in a broken world. Most who study heavily into spiritual warfare would probably disagree with me there. We must also never obtain an attitude that says "the devil made me do it" when in fact it is our own fault.
If a situation is "demonically initiated" I find that it is usually a situation that snowballs quickly and into a big ordeal and then later leaves us wondering "what the heck was that all about?!". Though that's not always the case. There is really no clear cut answer or methodology in discerning whether something is demonic or not. One of the spiritual gifts is discernment. If someone with the gift of discernment(usually intuitive people), picks up on something that concerns them their responsibility is first to pray for the situation/person. Than if it is God's will, act accordingly.
Wisdom & discernment has been one of the most needed gifts in the body of christ. Without it stupid and freaky things happen which show the wrong picture of Jesus thus doing only harm, despite good intentions.
As with any spiritual gift, it is developed within the presence of God. We come to the presence of God during our times of devotion/worship. Times in which we give our Father undivided attention. It is then exercised when we apply what we developed in our daily lives. Somewhere in the bible it says that God inhabits the praises of His people. So in my mind, where God is no demon can stand to be. This is the key or at least the beginning to true spiritual warfare.
2 years ago