 Because they know the weak saints will not be in a house of worship. They know that they are the weak ones. They don't want to study the Word of God. And as a result, they know they can get them. If you won't receive the truth, you're wide open for anything that comes along. And I've been amazed at some intelligent people. They'll sit in a church, hear the gospel, reject it, and then turn up the next thing you know following the wildest cult.