Why does God need love? He needs love because love is something that exists only in a reciprocal relationship. Without being a God who needs love, He would be unable to make a relationship with the created world and human world.
Why did God create human beings?
Explanations from Sun Myung Moon's speeches
The purpose of our creation is love. Life was created based on God’s love; God did not generate love by first creating life.
Joy arises through a relationship. Alone, you cannot receive the stimulation of joy.