We overcome our spiritual enemy, Satan, and his minions, by our faith. The writer of Hebrews gives very clear commentary on this biblical fact from the story of the battle of Jericho (Joshua 6:1-27).
By faith the walls of Jericho fell down after being marched around by the Israelites for seven days. (Christian Standard Bible)
The apostle John expands upon this principle with even greater clarity.
1 John 5:4
For every child of God defeats this evil world, and we achieve this victory through our faith. (New Living Translation)
The Israelites walked around the walls of Jericho by faith for seven days. They had been given one demonstration after another that God's word and His power could be trusted. Think about it. They knew that it was the Lord who opened the Red Sea, defeated the Egyptian army, kept them alive in the desert, opened the Jordan River, and brought them safely into the promised land. How could they do anything else but believe Him? Even though the plans didn't make a lot of sense, they could ultimately trust God and they expressed their faith by obeying the instructions that God had given them. Likewise, when we accept God's plan by faith, we invite God's presence, and that's what guarantees victory. You see, the fall of Jericho should be a great encouragement to us. As God's children we must learn to trust His promises and obey His instructions, no matter how impossible the situation appears to be.