To be a child of God means access. We know God is attentively listening to us and watching us. Think about what it takes to get in to see the president of the United States. Only people who merit his time and attention would be allowed in.
They must have credentials, accomplishments, and perhaps a power base of their own. If you are one of his children, however, it is different. In the same way, the God of the universe is “mindful” of you (Ps 8:4). Prayer is the way to sense and appropriate this access and fatherly love, and to experience the calm and strength in one’s life that results from such assurance of being cared for.