"Though you lose your soul, you shall gain the World." is the first of the Mandate Catechisms. (In tDtCB and WP, the same catechism is phrased as "Though you lose your soul, you shall win the world.)
Matthew 16.26 from the Bible is:
King James version: "For what is a man profited, if he shall gain the whole world, and lose his own soul? or what shall a man give in exchange for his soul?"
I cannot imagine this is a coincidence. Thoughts on the parallels here?