I would want to see and read the warrant before letting the police inside my home. If they refuse to show the warrant and they push pass me to enter, I will make a mental note of it.I think you mean you would not give them permission to enter.
Which for the record I probably wouldn't do if they showed me the warrant. I wouldn't want it on record that I gave permission if it turned out the warrant was faulty.
But I am fairly confident that the police will never come knocking on my door with a warrant, or, if they do, that they are at the wrong house.