I am pretty sure I watched this movie on HBO in the late 80s or early 90s. It began with some young kids travelling through what appears to be some really green countryside to a property inherited by one of the kids from maybe grandparents. When they get there, there is only partial walls and the door and grass has grown up all around but when they open up the front door the house is completely intact with walls and you are taken back to when the grandparents had lived there. The grandmother had her hands on a book, maybe a bible, and the grandfather was trying to hold the door shut because something was trying to get in. The walls got all wavy and the house exploded. Then you see some of the kids walking in the grassy part while the others were looking in the house. They stayed the weekend and there were some sort of creatures after them although I dont remember seeing what they were and there were I think four daggers to kill the creatures with. I remember the first part vividly and I remember the movie scaring the crap out of me. Please help as I’d like to watch again to see if it was as scary as I remember!