I think there's highly evolved entities out there within even our own solar system who help guide humanity, or at least make sure the playing field we live in has the full opportunity to freely choose a world of love and light or a world where people are in fear and it has a pecking order.
Have you noticed that throughout our known history, we have never completely annihilated ourselves, nor have we had a truly eutopian society. We've always kind of straddled the middle road, with varying degrees.
I think these higher evolved beings can't be seen because they shield themselves from us. Think of it like a radio. There are many channels, completely independent from one another, yet they are part of one radio broadcast system. That is how we are. We are only able to tune in to one particular vibration (our planet/life at the moment). I think these higher evolved beings can freely tune in to our vibration whenever they please, and that's why some UFOs suddenly dissappear.