Bible Verses About Self-Denial: Danger of neglecting

For whoever desires to save his life will lose it, and whoever will lose his life for my sake will find it.

For what will it profit a man, if he gains the whole world, and forfeits his life? Or what will a man give in exchange for his life?

but I beat my body and bring it into submission, lest by any means, after I have preached to others, I myself should be rejected.