Bible Verses About Warfare of Saints: The world

These things have I spoken unto you, that in me ye may have peace. In the world ye have tribulation: but be of good cheer; I have overcome the world.

For whatsoever is begotten of God overcometh the world: and this is the victory that hath overcome the world, even our faith.

And who is he that overcometh the world, but he that believeth that Jesus is the Son of God?