Revelation 2:16-17

So repent, then, or I will come quickly to war against them with the sword of my mouth. But the one whose heart is open, let him listen carefully to what the Spirit is presently saying to all the churches. To everyone who is victorious I will let him feast on the hidden manna and give him a shining white stone. And written upon the white stone is inscribed his new name, known only to the one who receives it.