Astronomy books always say that the Moon is gradually spiraling away from Earth. At present, the Moon gets 3.8 centimeters farther away from Earth every year, and it was much closer to Earth in prehistoric times.
But the Moon’s outward spiral is dwindling as its distance from our planet Earth decreases and its tidal forces get weaker. This alone should be enough to prevent it from ever leaving orbit around Earth completely. Another factor is that the Moon’s satellite’s tidal pull slows down Earth’s rotation by 2 milliseconds per century. Given enough time, the Moon’s satellite’s pull will eventually slow down planet’s rotation so that Earth takes a month to rotate (however how long a month may be by that time). At this point, Earth will be fixed with one side facing towards the Moon, just as the Moon is already fixed with one side facing towards Earth. At this point, Earth’s tidal bulges will become “frozen” in place, and incapable of influencing either Earth or Moon any longer.