We are One. We are all connected and we are all part of the One Energy Field, or the One Supreme Mind, or the One Consciousness, or the One Creative Source. Call it whatever you want, but we are all One. As you think negative thoughts about another you are separating yourself from the One, and your negative thoughts will return to harm only You. You have been given free will to choose, but when you think negative thoughts and have negative feelings, you are separating yourself from the One and All Good.