It's A Big World Out There - Rex Crawford - Bog

From the deepest, darkest corners of existence, there have been enemies lurking. They have been patient and cunning. They are able to anticipate all strategies of attack with the most unexpected defensive maneuvers with ease. This enemy knows man better than men know themselves. Mankind is on the verge of coming face to face with this greatest of all threats that has existed throughout history. This enemy has been closing in on the human race for centuries. They are the Cacodemons.
Off-world observers recognized the threat and devised a careful plan to help the people of Earth, so that they might be ready and have a fighting chance of defeating them. They are called Rapah, and they are strategically assigned to work with millions of key people on Earth, one-on-one. Their methods, though covert, are intended to give mankind the advantage that will be needed when the war begins in earnest. But time is running out, and the threat is ever-increasing.