What Jesus teaches us is that our actions should reflect our words and our words become alive in our actions. Let our yes be yes and our no be no. To be holy means that there is no division between our words and actions. James tells us to be doers of the word and not hearers only. Anyone can say "I love you." Words come easy. But true love is shown in deliberate signs of love. In adages we are familiar with, we would say: "Back your words with action", or "Don't just tell me, show me," "Words are cheap. The proof is in the pudding", "Do it darn it, do it". 

aintliness means living without division between word and action. If I would truly live in my own life the word I am speaking, my spoken words would become actions, and miracles would happen whenever I open my mouth.