Righteousness is often costly to the man who keeps to it at all [costs], but in the end it will bear its own expenses and return an infinite profit. A holy life is like sowing seed: much is going out, and apparently it is buried in the soil, never to be gathered up again. We are mistaken when we look for an immediate harvest…. Courage, brothers! We need not be in a hurry. Let us in patience possess our souls, for soon shall our souls possess [a harvest of] light and gladness.
I have heard another teacher put it this way:
You not only reap what you sow: you reap more than you sow, and later than you sow.