It depends, really. If some aren't working for you then it's either 1) The spell doesn't work. 2) There isn't enough belief inside you or 3) You're doing it wrong.
Make sure those 3 things don't happen! If it doesn't work then it's a false spell it may be for another thing like demons so be careful about what you click on. There is a tutorial on how to get spells to work but I'm not sure if this website allows links so, since I am not sure of that I will not be giving the link due to me possibly getting a gag. But if you want to hear more about it just mail me I will just tell what is in it :)