Karma has no expiration date.  

In our ignorance and delusion, we do not truly understand karma. What we think, say, and do will assuredly come back to us, just as surely as if we threw a ball against a wall. The cycle may take a million lifetimes, but a cause will give rise to a result—our karmic ball will bounce back.

Very likely many people will think, “Wait a minute, I believe in karma!”

We need to think again.

Do we really believe, really understand?

Have we become even a little irritated with someone or something today? That was anger, and we have not understood.

Have we declared “I want pizza tonight!” (and nothing else) or thought “Yes, that gap is enough for me to get into the other lane.” That was greed—for taste, for self-interest.

If we still have ignorance and delusion, still feel anger and craving, then we have not really understood causality. And instead of planting seeds to be born in the Pure Land, we are continuing to plant the wrong seeds, those that would see us suffering in samsara, over and over.