ABOUT "AMEN"
Then, of course, there is the Amen. It signifies faithful and true. Some suppose it is taken from the initial letters of adoni melech neetnem: My Lord, the Faithful King. In the Greek, it means, "So be it," or "Let it be so."
The main point is that Jesus says to end our prayer with a rock-solid affirmation that what we have prayed is indeed our desire and through Him, and that we fully expect it to be accomplished.