2 Chr 20:20, Jn 16:33, Rom 8:35-37, 1 Jn 4:4, 1 Jn 5:4
In the Old Testament, Judah in the South defeated Israel in the North. Because Judas the South depended on God. (2 Chronicles 13:18)
2 Chronicles 13:18 Thus the children of Israel were brought under at that time, and the children of Judah prevailed, because they relied upon the Lord God of their fathers.
In the Old Testament, Jehoshaphat told the Israelites that if they trust in God, they will be victorious. (2 Chronicles 20:20)
2 Chronicles 20:20 And they rose early in the morning, and went forth into the wilderness of Tekoa: and as they went forth, Jehoshaphat stood and said, Hear me, O Judah, and ye inhabitants of Jerusalem; Believe in the Lord your God, so shall ye be established; believe his prophets, so shall ye prosper.
Jesus conquered the world. So, we just need to believe in Jesus, be bold and enjoy peace. (John 16:33, Romans 8:35-37, 1 John 4:4, 1 John 5:4)
John 16:33 These things I have spoken unto you, that in me ye might have peace. In the world ye shall have tribulation: but be of good cheer; I have overcome the world.
Romans 8:35 Who shall separate us from the love of Christ? shall tribulation, or distress, or persecution, or famine, or nakedness, or peril, or sword? 36 As it is written, For thy sake we are killed all the day long; we are accounted as sheep for the slaughter. 37 Nay, in all these things we are more than conquerors through him that loved us.
1 John 4:4 Ye are of God, little children, and have overcome them: because greater is he that is in you, than he that is in the world.
1 John 5:4 For whatsoever is born of God overcometh the world: and this is the victory that overcometh the world, even our faith.