mattie: if you believe that ALL spiritual entities can be driven out so easily then you have been fooled, and have probably succumbed to one or two such entities' wills.

The power of your 'go away' has to be stronger than the spiritual entity's 'I don't want to' in order for it to be successful. 90% of the time, spiritual entities you meet are cowardly scavengers who just want to nibble on your energy and don't want to get into any kind of conflict that can drain them (they have a much harder time recharging than humans do), so even if they are stronger than you they'll leave you alone and go look for a limping rabbit instead of a fiesty hedgehog. Sometimes, however, you draw the attention of a bigger demon who gets it into his spiritual mind that you would make a good regular meal and attaches himself to you (or attaches you to him). The process of him doing so we won't go into.

Know that these entities can: resist you, lie to you, drain your energy, guide your understanding (but not outright change your mind), guide your emotions (but not outright change your feelings) and more.

The process of dealing with these greater entities is more difficult and if you know someone who can exercise them that is best.