Adam Clarke on John 1:12

Gave he power - Εξουσιαν, Privilege, honor, dignity, or right. He who is made a child of God enjoys the greatest privilege which the Divine Being can confer on this side eternity. Those who accept Jesus Christ, as he is offered to them in the Gospel, have, through his blood, a right to this sonship; for by that sacrifice this blessing was purchased; and the fullest promises of God confirm it to all who believe. And those who are engrafted in the heavenly family have the highest honor and dignity to which it is possible for a human soul to arrive. What an astonishing thought is this! The sinner, who was an heir to all God's curses, has, through the sacrifice of Jesus, a claim on the mercy of the Most High, and a right to be saved! Even justice itself, on the ground of its holy and eternal nature, gives salvation to the vilest who take refuge in this atonement; for justice has nothing to grant, or Heaven to give, which the blood of the Son of God has not merited.