If someone's house was on fire, and the children were inside asleep -- should the parents get rightly upset if someone tries to wake the children up to flee the fire?
Because that is essentially what these Christian missionaries believe themselves to be doing.
Are their parents also equally upset with the satanic bilge water that is pumped into their houses via the TV airways, or the brainwashing that their children are exposed to during their school hours?
Jesus commanded “Go ye into all the world and preach the gospel.” And that is what they have been doing since Jesus was here.
So if Moslems or Mormons or Scientologists tried to convert your children without your knowledge, would that be OK with you? They also "believe themselves" to be saving your children from a terrible fate.