Dear Larry:
I praise God that our web ministry has be useful to you. It is good to hear.
Prayers and symbols have influence over demons in two ways. First, it is the faith behind the prayer or symbol that gives the symbol significance. The Bible tells us to "resist the devil and he will flee" (James 4:7). Resisting the devil comes from our faith. Against faith the devil has no power. As Jesus taught that the faith of a mustard seed can move mountains. If faith can move mountains it can certainly move a puny demon.
The second way that prayers and symbols have influence over demons is, in the case of prayers, it is a petition to God to act against the demon (to rebuke, bind, and cast out). In the case of "blessed" symbols, such as Holy Water or a religious medal, the demons may be afraid of the "imprint" of God placed upon that object by virtue of the blessing. Although a demon may also shy away from an unblessed religious object because of what it represents — such as a Cross because it represent the means in which Christ defeated Satan and death — blessed objects usually have more effect due to the imprint of God upon the object.
Prayers, it must always be understoonr, are not magick nor incantations, and symbols are not talismans. The power of prayer is in the faith of the person praying the prayer and the power of God to whom the prayers are directed and to whom has all power over all the universe. The power of symbols is also in the faith of the person using the symbol, in what the symbol represents, and in the power of God in His presence (fingerprint) placed upon the object when it is blessed.
The Name of Jesus Christ is one of the most powerful prayer and symbols. It is a prayer in that it is calling upon Christ, and it is a symbol in that the name of Jesus Christ is the "name" (symbol) of God in the Second Person of the Trinity and represents the redemption of man and power over death.
I would advise using the name and title when referring to Jesus — that is, using "Jesus Christ". The reason for this is that it has been known that some demons will go by the name "jesus", but obviously they are not the "Christ." Thus, the specific name of Jesus Christ can only refer to our Lord and Savior.
As for why some demons seems to flee easily and others do not cannot be answered definitive — there can be many varied reasons. One obvious reason speaks to the relative rank and power of the demon. Obviously a demon with the rank of "Private" will be less powerful than a demon with a rank of "General".
In addition, the reason why some demons are harder to get rid of is because of the nature of the bondage with the person. Demons that infect a person due to curses, for example, are harder to deal with. Demons present in a person's life due to sexual sins can also be hard to deal with.
But any demon, regardless of rank, can be nearly impossible to cast out if the person is unwilling to repent of the sin in their life, which in turn allows the demons to remain attached to them. It can be equally difficult to get rid of demons of the client is unwilling to get rid of all "hooks" in their life that demons use as an excuse can hang on to the person's life.
Freedom from demonic oppression or obsession is among the hardest cases we experience. Such case involved a lot more than merely asking God to cast out the demons. To effect true Freedom every single "hook" in a person's life that a demon can hang onto needs to be removed. When I say this I mean every potential hook, even if the hook is not the issue that allowed the demon entry in the first place. Demons will hang on to anything, no matter how trivial, that will allow them to remain with a person. In cases of oppression and obsession the deliverance process can be very long. If we discern that the person is actually possessed, then we refer the client to his bishop.
Thus, the process of Deliverance Counseling is about finding all these possible hooks and working to remove the hooks. Then, and only then, can the demons be cast out in such a way as to most likely keep them out.
God Bless,
Bro. Ignatius Mary