When Jesus says blessed are the merciful for they shall receive mercy, he assumes that you really can't be merciful until you've received mercy in the first place. Mercy is not a deal, but an ongoing lifestyle. We receive mercy then we show mercy and as a result we receive more mercy, and as a result, we then show more mercy-and on and on.

 It's like we're rolling a snowball downhill. We start with a small one, maybe the size of a baseball. As we toss it down the hill, immediately gravity starts to pull it farther downhill. As it rolls over, of course, it collects more snow. Now it's bigger and heavier, and so gravity pulls it even harder. It rolls over even faster, and collects more snow, and gets heavier, and rolls faster. And so on. Before you know it, it's a huge ball, bounding down the hill. That's how it is with mercy: The more we receive mercy, the more we give mercy.