/worldspawn bugs

I was making a map and i wanted to set world spawn in the house i made for it in the sky, so i did /worldspawn and it said that the coords that i was at is now the world spawn, so i did /kill to see if it worked and it didn't it, every time i killed my self or had a mob kill me it spawned me where every it wanted, but still kinda near the world spawn i set up.