Then you add that to the fact that the most popular music genre for today's kids is now hip-hop and rap music. If you stop and listen to the music you will see there is a huge problem there with the language. You know, I think we can see that there is a real problem, and as a mother of three teenagers, I fight the culture every day in my house.

Crosswalk: With so many well-intentioned parents out there, why do you think parents fail to stand up to negative cultural influences?

You know, over the email that I've read -- and this answer is really based on anecdotal stories from parents that I interact with on a daily basis -- I've pretty much boiled it down to three reasons:

Number one is that parents are either too tired, or too lazy to fight the culture. They feel overwhelmed. They feel helpless. And so my message to group number one is this: The mass marketers with their worldviews are never too tired to market to your children. They are never too lazy, and they will never give up.

The second reason I find is that parents seem to be too distracted. We're too concerned about our own careers, and all the things that we want to do that we're just too distracted to pay attention -- not to what our child wants, but to what our child needs.

And in the third arena -- which I think is probably the most distressing -- a lot of the parents today grew up in the 60's "Me-generation" and these parents never learned as kids to deal with peer pressure. So as adults they still don't know how to deal with peer pressure, and they don't know how to teach their kids either.

Crosswalk: Those in favor of "freedom of expression" in the media argue that if parents don't want their kids exposed to something, they should just change the channel. Why is this no longer enough?

Hagelin: You know my answer to that is, change it to what? You see prime time family television that is suppose to be the family hour and the numbers of sexual incidents in there and the language is so bad that every parent has to jump for the remote control. And that is not even counting the commercials.

I would say a central message in Home Invasion is this: There is a lot of good that exists through modern technology. So I say to parents -- Maintain the good and get rid of the poison. Reclaim your home. Get Internet filters for Internet connections. Never let a child have a computer in their bedroom. If you have cable TV, make sure you get parental control locks on it.

And it goes beyond media we usually think of as entertainment. It also goes into what our kids are bringing home from their schools and their textbooks. When was the last time you picked up your child's textbook and looked at it? Most parents have no clue what the messages are that have made it in through the educational bureaucracy and establishment.

Crosswalk: In your book you note that one of the most frequent comments you receive from parents is, "I know I need to fight the culture, but I don't know how!" So could you share some overall guidelines parents can follow to raise godly kids in a culture gone mad?