I think what Bro. Paul has said is spot on. The enemy has already been defeated. His only real power against us is the power of deception. He is a liar and the father of lies. In that case, the real spiritual warfare in our personal lives is described in 2 Cor. 10:5-6. A born again believer has the authority and power through Christ to defeat any attack of the enemy in this realm. So if we are being defeated, it is because we are allowing ourselves to be defeated, perhaps through ignorance, apathy, inattention to the things of God, etc..
As far as rebuking demons, there is scriptural example of this every time a demon was cast out of a person. Jesus did it, and taught His disciples about it. The apostles did it. Sometimes the demon would be causing behavioral manifestations in the person, and sometimes the demon would be causing a physical manifestation of sickness or disease.
As far as demonic influence over regions goes, I do believe scripture teaches that this sometimes happens. That is what principalities, in my opinion, refers to. In speaking of Pergamos, Jesus said that it was where Satan's seat was. This indicates a Satanic power ruling over that city. However, I have never seen anything scripturally that indicates that we as believers are called to take any authority over these things or to "do battle" with them in an effort to pull them down. As a born again believer, these things have no power or authority over me. They have already been defeated, and their time of authority over these areas is short. I think the whole spiritual warfare movement got off in this area. I recall hearing about a group that went to ancient Ephasus to "pull down the principality of Diana of the Ephesians over that area". I honestly see it as a great waste of money and time based on error.
In saying all of this, I do realize that we often face very negative things in our lives that we think of as trials. I would question (or discern I guess) where these things come from.
Remember that we are told in 2 Cor. that the weapons of our warfare are not carnal, but mighty through God to the pulling down of strongholds. We are then told that our warfare is against imaginations, thoughts, and things that come against the knowledge of God. In Eph. 6 we are told that we wrestle not against flesh and blood, but against principalities, power, and spiritual wickedness in high places. So the battle is in the spiritual realm.
The physical things that we face often have spiritual causes, but they often have "natural" causes as well, as a result of living in a sin cursed world. For example, we get sick. Sometimes that sickness is natural, the flu for example. Sometimes that sickness is spiritually motivated and is the result of someone being bound by, for example, a spirit of infirmity. But I would never say that a sickness comes from God. While I may turn more attentively to God as a result of that sickness, I do not believe it came from God for that purpose. For then, what would I do with the admonition to love my wife a Christ loved the church? Would I think it a Godly thing to intentionally expose my wife to disease in an attempt to make her turn to Christ? Sickness is a manifestation of original sin in the flesh of mankind. Through Adam's sin came sickness to the human race. I can open myself up to sickness through sin, or I can get sick simply because someone with the flu sneezed in my face.
But I would not make that same statement concerning things that I simply think are uncomfortable to whatever degree. For example, suppose I ignore God speaking to me about quitting my job and going another direction. I might have good reason to ignore him in my own mind, money issues, security, retirement, and a host of other "responsible" decisions. But my ignoring God causes me to step out of His grace for my life. Things go south and I lose my job. Perhaps God did say, "Ok, I will have to move you by turning your boss against you." I struggle to make ends meet. I lose my car and have to buy a junker. I lose my house and live in a small apartment. My family struggles to eat. Definitely not pleasant or easy on the flesh. Then, I turn to God and repent of my disobedience. I go His direction, step back into His blessing, and find my financial house coming back into order as His blessings flow. This might seem a great trial, but it is only some discomfort of my own doing.
However, if I am doing God's will, it is inevitable that Satan will come against me and that I will fight battles. Perhaps I obey and the enemy comes against me in the financial realm. I begin to struggle. But, knowing I am in God's will, I persevere, knowing I am fighting, not a financial war, but a spiritual war. I can resist the devil in my own life. I can, I believe, command Him to leave my finances alone. I can continue to stand in faith for my circumstances, but I need to be sure I am in God's will as a foundational basis for my faith.
I hope you see the distinction I am trying to make. I don't believe God sends evil things to try us. I do believe that any time we step out from under His grace, we open ourselves up to the enemy to do what he naturally does in all cases, steal, kill, and destroy. I do believe that God may ask us to step into situations that will be very hard on our flesh, that may lead to our death or martyrdom, but will advance His kingdom. God said that He would show Paul how great things he must suffer for the sake of the gospel. And he did. After all, what is my physical life? I do believe that Satan will come against us and that we can take authority over those things. I also believe that we need revelation of the Holy Spirit to discern the difference between these things so that we might react appropriately.
Hope that all makes sense.
