The greatest father-child relationship in history that we can learn from is Jesus and his father. The way that Jesus interacted and related to his Father allowed him to live the life he did here on earth. And in the same way we are to imitate the intimacy of that relationship. Knowing we are starts with knowing who we belong to. The truth is that we have been created in the image of Jesus as sons and daughters of our heavenly father. This truth allows us to live life with purpose and freedom, in pursuit of doing "the Father's" will. 

John 8 : 32
"Then you will know the truth, and the truth will set you free."