From the Dhammapada, the sayings of The Buddha:

Do not think lightly of evil, saying "It will not come to me".  Even a water-pot is filled by the falling of drops. Likewise the fool, gathering it drop by drop, fills himself with evil.

Do not think lightly of good, saying "It will not come to me".  Even as a water-pot is filled by the falling of drops, so the wise man, gathering it drop by drop, fills himself with good.