Guard your thoughts and emotions through constant reflection on your inner self.
When confronted with undesirable circumstances and people, our first instinct is to get carried away by our emotions - anger, impatience, fear and discouragement. Even in our achievements we can lose ourselves to pride.
To protect and cleanse our inner selves, we should constantly check the way our hearts react to external situations, dwelling neither on our emotions nor the outcome of the situation, but rooting our hearts instead in the Lord.