What does the Spirit of adoption mean?

In Romans 8:15, Paul speaks of having received the Spirit of adoption, which signifies our intimate relationship with God. This spirit allows us to address God as 'Abba, Father,' reflecting both closeness and reverence. This adoption is not based on our righteousness but is a gift received through grace, emphasizing that we do not come to God on the basis of our performance but as His regenerated children through faith in Christ. It assures us of our place in His family and the privileges that accompany it.