Because God sympathizes with us and wants us to experience his power and dignity and image alive and at work in us, he becomes one of us and shows us how it’s done. God desires to proclaim men as victors, so he becomes one and wins. Christ destroyed death, brought an end to sin, abolished corruption, banished ignorance, manifested life, declared truth, and bestowed incorruption.
Of particular importance to those who claim God is unjust, or unfair, is the means through which God accomplished his victory. He could have accomplished it by force, wresting lordship away from Satan mano a mano, but then the devil would have had cause for complaint. After all, the disobedience of Adam resulted in the abdication of humanity's dominion over the earth. Satan had rightly and justly won his lordship, and God would have had to either cheat, break his own rules, or bully Satan in order to get it back.
No—in order to be just, God had to win back the lordship over the world. And the only way he could win back what humanity had lost was to become human himself. So he did. Thus the disobedience of Adam was undone by the obedience of Christ.
Obedience was the means of his triumph and ours.
We could never have escaped the devil's dominion without the victory of Christ on the cross. The passion of Christ brings us courage and power. He, through his passion, ascended on high, made captivity captive, gave gifts to men, and gave us power.
What is the nature of that power? According to the Second Testament, it is power to rule (Revelation 1.6), power to overcome evil (Ephesians 6.10), power to defeat the agents of the enemy (Luke 10.19), power to witness (Acts 1.8), power to perform miracles (Acts 6.8), power to demolish strongholds (2 Corinthians 12.9), and power for the new creation (1 Corinthians 15.43).
But we can only have this power because Christ has won it back for us. He has "tied up the strongman" (Matthew 12.29), carried off what the devil once owned, and given it back to God's people.
God could have cheated, but instead he allowed his divine wisdom to be put on display, making a show of those dark powers and returning humanity to its former, God-given, glory.