Maybe if Christians were more knowledgable about their faith they would not find themselves tricked.
If Christian parents rear their children to think that teaching of Scripture and the tenats of their faith are a Sunday only matter why of course they will be more easily seduced away from Christianity.
If the only Christian education a child gets is Sunday school a denomation should not be surprised if the faith does not stick.
Maybe Satan doesn't exist and the human condition is perfect and we don't need to fret about such things or resist a sophisticated cult organization concealing itself as Christianity, or help our fellow Christians that may lack perfect knowledge.