The film can be vague, but it should be understandable by your audience. Also, you need to give enough interesting character dialogue and show progression not to lose your viewer. Following general horror cliches with creepy kids, occult imagery, scary faces, and frightening toilet doors are not enough.
The Pond contains a very hazy and muffled general idea about hell, God, religion, and humanity. This is not, however, well communicated in the film besides some random disconnected pseudophilosophical dialogue delivered through acting so stiff its density cannot be penetrated by any known material in the world.
So, if you are not willing to bleed your brain you will most likely just feel extremely bored and confused throughout the film. Most viewers will catch the obvious symbolism (and homages to the classic films and literature) like the seven deadly sins projected through the characters, seven days of creation, and the circles, oh man, the circles. But these details serve no real purpose but to make the last 5 minutes of the film almost understandable.
Confused viewers might think this movie is too deep and smart for them just because it makes no sense - but it's not.
They should've just stuck to something understandable and time-tested. Want to show a visual representation of hell - borrow more from Jacob's Ladder, 1408, whatever. Want to tell a creepy occult story with interesting ideas buffed with existential crisis? Copy True Detective Season 1. Oh, wait, they have already done that. Want to explore religion? Make a dialogue-based film like The Man From Earth in the cool location you have, why not.
Just not everything at once.
I can't recommend this. 3/10, 1 star for the looks and visuals, 1 for the soundtrack (which felt confused about what it was trying to follow), 1 for Paul Leonard Murray's acting.