1 John 5:4-5:

For whatsoever is born of God overcometh the world: and this is the victory that overcometh the world, even our faith.
Who is he that overcometh the world, but he that believeth that Jesus is the Son of God?

See also:

Who You Are and What You Have
You Win!
The Temporary Curse
Objection: My Trials Only Come to Make Me Strong