Some people go to extensive lengths to protect them and their family from the bad influences in the world. Some put up computer blocks against pornography. Families have the "drug-free" talk with their kids. Families have rules, standards, etc. etc. etc.
Sometimes we put up extensive protections against something in particular, but then forget about protecting something else in another area. Like, putting a filter on your computer and then not setting restrictions on what kinds or standards of movies your family watches.
It's like this picture here:
You go to extensive work to protect your family. Just like the bird spikes (whatever those things are called on the window). But, just like the bird, worldly things will try to find another way to sit on your wall.
Or, you know, get into your home.
Think about what you can do to further protect your home and family. Don't let in those worldly birds!