When someone feels the need to bully another person, it usually is because they have a deep-seated feeling of inferiority that fuels their anger. In order to deal effectively with a bully, one must first determine the cause of his feelings of inferiority, then let him know that being a bully will not fix the cause. In the case of a child, he should know that being a bully will cause him to be hated and despised.
Doing what God demands in order to defend yourself and the kingdom of God may not seem natural. However, you can never allow yourself to be bullied by anyone. When dealing with a person, you can command his spirit through the power of the indwelling Holy Spirit Of God. When confronted by a demon, use the sword of the spirit to behead him, and he will be forced to return to his place in hell. Ask the indwelling Holy Spirit Of God to show you how to use the sword of the spirit to behead any demon that is bullying or harassing you.
The Lord God Father in Heaven, El Elohim