The spiritual soul is the "form" of the body. Man is not the union of two natures. In man, spirit and matter form one nature. God creates every spiritual soul immediately. It is not "produced" by the parents and does not perish at death. It is reunited with the body at the final resurrection.
When Paul writes about "spirit, soul, and body" (1Thess 5:23) he used the word "spirit" to mean that the soul has a supernatural goal of union with God. The biblical word "heart" also means the place where the person decides for or against God.
Taken From The Compendium - Catechism Of The Catholic ChurchRead More
At the Last Supper with his apostles on the eve of his passion Jesus anticipated, that is, both symbolized his free self-offering and made it really present: “This is my Body which is given for you” (Luke 22:19), “This is my Blood which is poured out...” (Matthew 26:28) Thus he both instituted the Eucharist as the “memorial” (1 Corinthians 11:25) of his sacrifice and instituted his apostles as priests of the new covenant. Please click here to learn more about Holy Mass, also known as the celebration of the Holy Eucharist.