At the right time, God sent Jesus. He sent Jesus to redeem those under the law.
Now that's all of us. We were born into this world under the law of sin and death. We were under the control of sin's power, slaves to sin. But no longer.
Christ went into that market place of sin and death and became sin for us. He paid the price. And once he did, he adopted us as sons and daughters and filled us with his Spirit. It is by His Spirit that we cry out "Abba, Father." Think about how your status has changed in Christ. You were once a slave to sin. Now you are a son or daughter of the King, and heir of God.