Because when Jesus was with his apostles they didn't have it, but when Jesus left, he told them he would send the teacher, the holy spirit. So since Jesus is back, there is no holy spirit anymore
Thats a Valid point
However the whole argument of this is Just hypothetical, similar to :
Santa clause brings Christmas cheer in the month of December. After Christmas, Santa leaves his spirit for the people, so that they can cheer up, all until next december.