Can a demon possess (as in 'own') somebody? No! In Ezekiel 18:4, God says clearly, "Behold, all souls are mine..."
Is demon possession rare? Not according to scripture! Mark 1:34, "...cast out many devils..." Luke 4:41, "...devils also came out of many..." Acts 8:7, "For unclean spirits, crying with loud voice, came out of many that were possessed with them..." Mark 6:13, "...they cast out many devils..." Matthew 8:16, "...they brought unto him many that were possessed with devils..."
Jesus sent fourth 70 disciples to preach the gospel and cast out demons, and they returned full of joy as they could see that this was a very real and important ministry. Now for Jesus to send out 70 men and they come back with praise reports of deliverances... that tells us that even though they were on foot, there were plenty of people in their area that needed deliverance! Luke 10:17, "And the seventy returned again with joy, saying, Lord, even the devils are subject unto us through thy name."
Are there different strengths of demons? Absolutely! The Bible speaks of different ranks of demons (Eph 6:12), and Jesus taught His disciples that some demons were so strong that they required a level of faith to cast them out that was only obtainable through prayer and fasting (Mark 9:29).
Aren't all demons the same? Absolutely not; they all have their own personalities, just like people do. There are different demons that serve different functions, such as some people are doctors while others are lawyers, etc. Some demons cause loss of hearing and loss of eyesight (Mark 9:25), while others cause infirmities, and others cause fear and depression (1 Samuel 16:14, "Now the Spirit of the LORD had left Saul, and the LORD sent a tormenting spirit that filled him with depression and fear." -NLT).
Do demons have names? Yes they do, just like God's holy angels have names (Luke 1:19, Judges 1:9). Often, the name of a demon will give you a clue as to what it does, the function it preforms, or the role it plays. Some of the demons in the Bible are known as deaf, dumb, infirmity, etc. (Mark 9:25, Luke 13:11).
Can demons return to the person whom they left? Yes, but this is mostly a concern for non-believers who have undergone a deliverance, and haven't accepted Jesus yet. Jesus warns the 'wicked generation' (sinners) that the demon can return with 7 even worse demons. If you are a believer though, and your deliverance has been complete (all the demons kicked out and legal rights have been broken), then this isn't a concern to you. However, if you go back and re-open the door(s) that let the demon in, you are re-welcoming him back in. But if we don't go back and re-punch that hole in our hedge again, we don't have have to go around worrying about it returning.
Can children have a demon? Yes, children can have demons just like adults. Anybody who is experienced in this ministry will testify to this. Mark 9:17-21, "And one of the multitude answered and said, Master, I have brought unto thee my son, which hath a dumb spirit... And he asked his father, How long is it ago since this came unto him? And he said, Of a child." The word child here in NT Greek is paidiothen and means 'from infancy', meaning the child may have very well been born with the spirit. Literally translated, the father was saying that his son had this spirit from infancy.
Can demons be handed down from one generation to another? The iniquity or curse in a parent or grandparent could be handed down, which automatically gives the demons the legal grounds to inhabit the child or future generation, but the demons themselves are not omnipresent and therefore cannot dwell within two people at the same time. Similar demons of the same kind (infirmity, fear, etc.) are usually what takes advantage of a generational curse or iniquity.
What does it mean to be 'demon possessed'? If you look up 'possessed' in the NT Greek, it gives you the word daimonizomai, which means to be under the power of a demon. For example, if you are under the power of a demon of fear, you will be fearful; if you are under the power of a deaf spirit, then you won't be able to hear.
Are there different levels of bondage? Yes, just like if you drink a little or a lot of alcohol, you will come more or less under it's influence. The more you drink, the more you come under it's influence, and likewise, the more you get involved in the demonic, the more you come under it's power (or influence).
Aren't Christians immune from demonic bondage? This is an unbiblical theology based on assumptions. In order to prove that Christians can't have demons, two things need to be considered. First, there must be an automatic shedding of demons at the time of salvation. Second, it needs to be proven that a demon cannot dwell within a soul (mind) or the body of a man while the Holy Spirit is united with the spirit of the man. Neither of these things can be proven Biblically. There are some verses that seem convincing, and I've had to use the Greek Lexicon before to prove that the interpretation of those verses was erred, but the bottom line is that nobody can Biblically prove that Christians can't have demons. I have seen from experience, that there are many Christians who are in demonic bondage. There are many deliverances I know of where Christians had demons cast out of them, and it made a day and night difference in their lives. This is a question that I could write a 20 page answer to easily, because it is likely the single most debated issue among those debating about this ministry. I have argued and debated with many very clever and sharp people over this, and have never been proven wrong. The Bible also gives plenty of proof that Christians can have demons, and deliverance for unbelievers is easily proven an invalid ministry according to the Bible, yet Jesus made it very clear that those who believe will be casting out demons. Those who oppose demons being cast out of Christians, rarely if ever do any deliverance work themselves for anybody, whether they be believers or unbelievers.
How do demons enter? The most common ways is through open doors (legal grounds), traumatic experiences, rejection, abuse, or generational (passed down). Open doors consists of things such as repeated sins, ungodly vows, curses (self-imposed, generational, etc.), occult dabbling, ungodly soul ties, unforgiveness, etc.
Can demons leave on their own without having to be cast out? From my experience, yes. The more you grow in the Lord, the more lesser demons will can shed, because you bring in the light, and it makes it uncomfortable for the demons to remain. I've seen where people have been set free simply by breaking the demon's legal rights. This doesn't always expel demons though, and there are many cases where the demons need to be cast out, but for many lesser demons, this can work.
Do demons always manifest when they are cast out? Sometimes they do, but not always. Sometimes all the person feels is a huge sigh of relief and a feeling like the evil spirit has left or a black cloud was lifted from them.
Is a demonic manifestation a sign of a successful deliverance? Unfortunately, demons can and do manifest without coming out. Therefore, this can be deceiving and dangerous to rely on manifestations as a sign of a successful deliverance. A successful deliverance will provide true lasting relief for the individual. To manifest, means to make itself known; this has nothing to do with being set free from them. It's often a good sign to run into a manifestation during a deliverance, but it doesn't necessarily mark a successful deliverance. I know some people go through a deliverance, a demon manifests, and then goes back under (stops manifesting), and everybody rejoices thinking the deliverance was successful, but the problem is, the demon only manifested but didn't leave. The person then walks away confused because they think the deliverance ministry is a weird practice that doesn't really solve any of their problems. Therefore, it is very important to not rely on a demonic manifestation to tell whether or not a deliverance was successful.
Is there anything you can do to reduce the demonic manifestations? Absolutely! Some important things to keep in mind, is to first try to cut off the demon's legal rights before casting him out, and also forbid them to harm anybody and tell them to hold thy peace and come out, as Jesus did (Luke 4:35).
Does having a demon mean that the person has lost their salvation until they are delivered? John 3:16 tells us the bases of our salvation, NOT whether or not we have a demon! The daughter of Abraham who was freed from a spirit of infirmity was an example of a believer who had a demon. Jesus never positively referred to somebody as a child of Abraham unless they were actual believers, and He slammed the Pharisees for considering themselves children of Abraham, because they didn't share in the faith of Abraham, and made it clear that they were not really children of Abraham. Therefore, if Jesus takes joy in considering somebody a child of Abraham, it's a honor and means that they are a true believer.
What are some of the symptoms of having a demon? Mental problems, irrational emotional breakdowns, physical problems that aren't easily cured by medical attention, repeated weaknesses to things such as anger, hate, lust, unnatural desires (homosexual, etc.) etc., irrational feelings, thoughts, desires, fears, depression, etc., irrational obsessive worrying, compulsive behavior and many more.
Is it good to ask a demon for it's name? It doesn't hurt a thing and it can be very helpful. You must be aware that demons can lie though, so you can't bank on what they tell you. But if you can get ahold of their name, it gives you a good handle to get their attention with. If somebody shouts "Hey you!" in a crowd, it probably won't get your attention, but if somebody shouts, "Hey Bob!" (providing that's your name), it will get your attention in no time. Having the demons name also gives you an idea of what his purpose and function is, as well as what other demons to look for in the person.
Is deliverance for today? Absolutely, it was live and well during the early church, and nowhere in the Bible does it say that we aren't to be casting out demons anymore, and the need for deliverance certainly hasn't diminished one bit.
Are we supposed to cast out demons? Yes! Jesus said that those who believe will be doing the works He did (which was healing the sick, raising the dead, casting out demons, etc.) and even greater (John 14:12). Jesus also said before He went back to be with the Father that those who believe will be casting out demons (Mark 16:17).
Who are we supposed to cast demons out of? Although it is possible and sometimes beneficial to cast demons out of unbelievers, the deliverance ministry is geared towards believers for a number of reasons. For one, it's part of the new covenant, which does not apply to unbelievers. Second, without Christ, you cannot remove the legal grounds the demon has in a person, therefore the problem hasn't been solved, it's only been stirred up. Third, Jesus warned that if you cast demons out of an unbeliever (sinner, wicked generation), it will come back with 7 more even worse demons and the man will be far worse then before (Matthew 12:43-45). I believe there are times when it is helpful to cast demons out of unbelievers, but that's not the focus of this ministry, Jesus said that this is children's bread (Matthew 15:26) and it is geared towards setting the believers free from demonic bondage.
Don't demons automatically leave at the time of salvation? No, this is an unbiblical assumption that nobody can back up with scripture (unless they twist it). Nowhere in the Bible does it say that we will automatically shed all our bondages at the time of salvation. Many demons cause health problems, and roughly half of the healings Jesus did in Matthew were actually deliverances from such evil spirits, therefore, if people automatically shed their bondages at the time of salvation, I would expect many many healings to automatically take place the moment they believe upon Jesus. Personally, I don't know of one of those cases. Cancer is known to be demonic in almost every situation, therefore, I would expect cancer to leave automatically at the time a person accepts Jesus, if we automatically shed all our demons when we are born again. The problem is, this is a faulty theology which keeps people from seeking the help they need, because it makes them believe that they can't have demons, therefore denying the problem. This belief that demons automatically leave at the time of salvation is what they are talking about in 1 Timothy 4:1, "Now the Spirit speaketh expressly, that in the latter times some shall depart from the faith, giving heed to seducing spirits, and doctrines of devils." The belief is unbiblical, and based upon assumptions, and furthermore, experience tells me others.
How can a demon dwell within a believer who has the Holy Spirit? Many believe that anybody who has the Holy Spirit is immune from demonic bondage. This theology usually stems from a faulty belief that the soul (mind) and the spirit are the same things. The moment we are born again, our spirits are reborn and the Holy Spirit is united with our spirit. The soul (mind) of a man is not instantly reborn as the spirit is, but rather we are told to be transformed by the renewing of our minds, which doesn't happen instantly. Our souls is where the dirt lies, and where the demons dwell, not our spirits. Therefore, there is no reason left to believe that a Christian is immune from demonic bondage, because their souls are usually on the dirty side until they are renewed over time. If the soul and the spirit were the same things, you would instantly be a perfect person, never to sin again, once you are born again. There would be no 'evil' left in you, no desires to do wrong, and you would hate it bitterly because you would be perfect in your mind/soul and united with God, therefore there would be no room to sin. In John 8:31-34, Jesus tells us that even though they were believers, they were held slaves to sin because they were ignorant of the truth; this proves that Christians can be in bondage to darkness. If a demon can affect our minds (souls), they can do an awfully lot of damage. Look at what mental illness can do to people through affecting the mind! They can cause the person to have unspeakable desires, thoughts, emotions, and do unthinkable things!
Can a person have a demon without knowing it? Yes. Two primary reasons for this would be, (a) ignorance, as they don't understand what is the true source of their problem, and (b) a demon(s) may be there, but isn't really doing anything noticeable at the time. Demons are like people in the sense that they can choose to be manifesting themselves or not; they can choose if they want to cause problems at the moment or not. When a person seeks deliverance from demons, and turns to the occult for help, the person who tries to 'deliver' them can just coax the demons to 'hide' and fake a 'deliverance', thus proving that demons can and do 'hide' if it benefits them. Sometimes a demon can lie dormant in a person's life, and then when that person enters the ministry, the demon manifests because it wants to shut the minister down and keep him out of the ministry.