What is the normal thing for a person to do for their own body?
The normal thing is to nourish and cherish one's own body, just as the Lord cherishes the church. A person with the right attitude toward life takes care of their physical body, feeding it, resting it, and not abusing it.
Les teaches that no man ever hated his own flesh; instead, the normal thing is to nourish and cherish it, even as the Lord cherishes the church. He presents this as a basic fundamental premise: if a person is normal and has the right attitude toward life, they will take care of their physical body. Then the spiritual admonition returns to 1 Corinthians 3: the body is not merely physical but is the dwelling place of the Holy Spirit and the temple of God on earth. Therefore, we are to treat it accordingly—feeding it right, resting it right, and not abusing it.
For no man ever yet hated his own flesh; but nourisheth and cherisheth it, even as the Lord the church: