Respecting human life means also respecting the body, temple of God’s gift of life and of the Holy Spirit. Meekness towards our body means giving it proper nutrition and care—as we would any gift from someone we loved and respected—and avoiding things that harm or incapacitate the body, even temporarily, such as recreational drugs or abuse of alcohol. Trafficking and selling such drugs is gravely immoral (see CCC 2290-91). We should also take proper care of our mind, not wasting our gifts on overuse of games and entertainment.
Mutilation or cutting of the body sends the message to our loving maker that we hate or dislike our bodies, the gift he gave us, or that he made a mistake when he made us. In addition, direct sterilization rejects God’s gift of our fertility, separating openness to life from the full expression of marital love. Surgery done for health reasons or to enable someone to proper social interaction is good, but surgery or permanent tattoos for superficial vanity tends toward a cult of the body (see CCC 2289), telling God that he didn’t make us beautiful enough, needing to fix what God got wrong. We care for our bodies as a gift, appreciating everything the loving giver has given us, but let us never treat or allow others to treat our bodies as a god.
In similar fashion, engaging in reckless activities and sports that senselessly risks a loss of life or serious injury also sends a message that we may value the thrill or the glory more than we do the divine giver of the gift of our body. Recognizing that all human life is a gift from God moves us to be concerned for the physical well being of everyone, promoting proper living conditions, food, clothing, housing, health care, education, and employment (see CCC 2288).
Scientific research is part of man’s dominion over creation in the service of man. This research must always respect the person, the meaning of our existence, and true human progress (see CCC 2292-95). Essential to respecting the person is his consent to any research or medical procedure. This is why experimentation on babies and human embryos goes against their dignity as human beings as they have no possibility of consent. Also experimentation must not put human beings at extreme or disproportionate risks of physical or psychological dangers.
The Catholic Church recognizes that donating blood and organs (if it doesn’t cause excessive health risks) can be an act of charity. Yet we must never donate an organ if removing that organ is the direct cause of our death, such as donating our heart when it is still beating and/or we are still breathing.
Human life and bodily health are not absolutes but are gifts to allow us to carry out our life’s mission. Ultimately, God is calling us to eternal life in heaven and we must be ready to leave this life in order to go to the Lord.
The dying should be given attention and care to help them live their last moments in dignity and peace. They will be helped by the prayer of their relatives, who must see to it that the sick receive at the proper time the sacraments that prepare them to meet the living God (CCC 2299).
Respect of the body leads to one of the corporal works of mercy, burying the dead:
The bodies of the dead must be treated with respect and charity, in faith and hope of the Resurrection. The burial of the dead is a corporal work of mercy; it honors the children of God, who are temples of the Holy Spirit (CCC 2300).
Autopsies and donating our corpse for medical research and education are also allowed, as long as provisions are made for the body to be buried with due respects after this purpose is finished. “The Church permits cremation, provided that it does not demonstrate a denial of faith in the resurrection of the body” (CCC 2301).