Parshat Kedoshim begins with the commandment to "Be holy." How do we achieve holiness? Nachmanides explains that holiness is the result of exercising restraint in areas that are permitted to you.

For example, let's say a person keeps kosher. It may be no great challenge for him to refrain from eating a ham sandwich. But the question is: When he sits down to eat kosher food, what is his frame of mind: Does he pronounce a blessing with concentration, appreciating God's gift of bounty? Does he eat slowly and with dignity? Does he focus on the fact that the ultimate purpose of food is to nourish the body - in order to have strength to do good deeds?

The story is told of the Baal Shem Tov, the great kabbalist, who looked out the window and saw his neighbor sitting at the dinner table. In the eyes of the Baal Shem Tov, the neighbor appeared not as a human, but as an ox. The neighbor was eating for purely physical reasons, just as would an ox (and the holy Baal Shem Tov was able to perceive this). Although the neighbor was acting in a permitted manner, it was not a holy one.

Sometimes a child will do something that demonstrates particular self-discipline, and the parent will say: "You're an angel!" But in actuality, the child is greater than an angel. An angel is a purely spiritual being, with no sense of "free will" to choose spirituality over the mundane. But we humans - every time we make such a choice - refine our soul, and achieve a level higher and holier than even that of angels.