Not everything unlawful is a sin, as Jesus clearly points out: “Hear  and  understand:  not  what  goes  into  the  mouth  defiles  a man,  but  what  comes  out  of  the  mouth… [as]  what  comes  out  of  the mouth  proceeds  from  the  heart,  and  this  defiles  a  man.  For  out  of  the heart  come  evil  thoughts, murder,  adultery,  fornication,  theft,  false witness, slander. These are what defile a man; but to eat with unwashed hands does not defile a man.” (Matthew 15:10, 18-20)

For an action to be sinful—for it to be good or evil—it must be a moral act that “proceeds from the [human] heart,” in other words, it must be freely chosen (see CCC 1749). Evil arises when we selfishly choose what hurts our relationship with God, as when a child hurts a parent by choosing to play with a toy over obeying his parent. Likewise, infidelity selfishly puts one’s emotional desires over his total gift of self to one’s spouse and to Christ.

Digestion and other biological acts arise from the body, not from the heart’s judgment and free choice.

Temptation is not Sin
St. Paul laments: “Wretched man that I am! Who will deliver me from this body of death?” (Romans 7:24). Like St. Paul, we experience the weight of passion and temptation, making us feel dirty as we consider past falls. But temptations and passions are not sins, despite how they make us feel. Only our response makes them sinful (if we give in) or makes them acts of love (if we say No to them).

The devil tempted Jesus—the Second Person of the Blessed Trinity—with bodily satisfaction, public acclaim, and worldly power (see Matthew 4:3-11; Luke 4:3-13). Also in the garden of Gethsemane Jesus experienced incredible sadness and overwhelming fear of approaching suffering, moving him to ask the Father to remove the cup of suffering from him (Matthew 26:36-46). Yet Jesus did not sin, but instead affirmed his obedient love for the Father by saying No to these temptations.

Adam and Eve were sinless when the serpent tempted them in the Garden of Eden. The delight of the fruit baited them to doubt God’s love and disobey his command (Genesis 3:1-7). This original sin spoiled their innocence, unleashing their bodily desires (passions are sensual emotions that incline us to some real or imagined good or away from some evil. See CCC 1763). Once disorder enters our passions and feelings they draw us to sin. As descendants of Adam and Eve—with the exception of the Virgin Mary, who was conceived without sin—we all have this disordered tendency to sin.

These temptations are not sins but are like hurdles for a runner. Hurdles are not obstacles for a properly prepared runner; he surmounts them to run with ease toward victory. God’s grace helps us overcome temptations to achieve victory over sin and death.

We are tempted by the world, the flesh, and the devil. While God created the world—people, places, and things—as good, a gift to help us fulfill our mission here on earth—we can turn to it for our ultimate happiness, turning it into a kind of god. We all know people who seek happiness by pursuing money, power, popularity, honor, fame… Those who have them may seem happy, but really they are not—just try living with one! Things don’t make us happy.

The flesh refers to legitimate desires for pleasure, but our flesh is weakened by original or personal sin. This includes desires for food, drink, sex, drugs, or other sensual pleasure. The pleasure itself is not sinful but is disordered when sought for its own sake. We all know people who are enslaved to some pleasure-addiction: pornography, alcohol, drugs, electronics, or even food, which robs them of the freedom to love with all their heart, mind, strength, and soul. Finally, the devil tempts us with arguments and excuses to doubt God’s love and to think that we can do things better, urging us to find exceptions to God’s law.

But temptations can be an opportunity to affirm our love for God. Jesus said No to the devil’s temptations, embracing his Father’s will out of love. Love can move us to overcome the fear of suffering and death, since “There is no greater love than for a man to lay down his life for his friends” (John 15:13).

May we take advantage of our passions and temptations to love Christ as he has loved us, saying No to ourselves and Yes to him.