Observation

The lamp of the body is the eye. Therefore, if your eye is undisturbed, your whole body will be bright. But if your eye is sly, then your whole body will be dark.
If, then, the light that is within you is darkness, how much worse will darkness be? No one can serve two masters, because he will either hate one and love the other or he will
focus on one and despise the other. You cannot serve both God and Mammon.

So I tell you, don't worry about your life, what you will eat and drink, nor about your body, what you will dress for. Isn't life more precious than food and body than clothes?
 Observe the birds of the sky that do not sow, neither reap nor gather in storehouses, but your Father in heaven feeds them. Aren't you much different from them? But
and who of you, by worrying, can add at least a few centimeters in his lifetime? And what about clothes? Carefully observe the lilies in the countryside and learn how
they grow up. They neither tire nor spit.