There was once a movement in Greek philosophy called Epicureanism. The bottom line is that life is brief, and we should drink deeply from the well of life now. The Epicureans said, "Eat, drink, and be merry, for tomorrow we die."
The Epicureans were partially correct. We should live "in the moment" but not necessarily "for the moment." Pure Epicureanism is living "for the moment," which will produce disaster for you now and later.
Conversely, living "in the moment" will help you to appreciate and savor what is happening to you. It focuses your energy on what you are doing. It keeps you from getting stuck in the guilt of the past or the anxiety about tomorrow.
Live "in the moment" – not "for the moment."