In our OT passage we read King Jehoshaphat declare God's strength, and Judah's own powerlessness. We then see God act in such a way that only He would get the glory for the victory. Judah did nothing, God did everything.
In our NT passage we see the same thing. The demon-possessed man, powerless to save himself, is delivered from the demons by the power of Jesus. The woman, powerless to heal herself, is healed instantly by the power of Jesus.
War, demons, and sickness - all powerless in the face of Jesus' mighty power.
But nothing demonstrates this fact more than our salvation. We are unable to save ourselves. We are dead in our sins. Without Jesus, we are doomed for eternity. But through the power of Jesus, who is mighty to save, we claim victory over sin and death. To Him be the glory, forever and ever, amen.
Bible In a Year Passage passage: 2 Chronicles 21-22; Luke 9:1-17