Thanks for the replies. This is how I ended up answering her:
Hi Jenny, Uncle Vince here!
Aunt Carol forwarded me some questions you had about some things that occurred to you at a recent retreat. These are really good questions, a) because it shows you are thinking about important things and b) because the particular questions you asked are important for understanding religion in general and our Catholic Faith in particular. I think I have some answers for you. You’ll need your or your Mom’s Bible for this so I’ll wait here while you run and get it.
Hmm hmm hmmm hmm…
Are you back? Good!
Let’s take the question about sacrifice first: why sacrifice?
The basic definition of a sacrifice is something you give up out of love. People give up many things for the benefit of those they love: parents sacrifice their time and money for their children, soldiers and firefighters may sacrifice their lives for others. This kind of sacrifice is an act of love.
Sometimes a sacrifice is made to make up for something wrong that they have done. Suppose a girl breaks a window with a baseball. The girl is caught and confesses, but the person whose window it is forgives her. However, it is only fair (or just) that the girl work (time) or find some way to help pay (with money) for the window. This kind of sacrifice is known as reparation, or paying what is owed.
But what does that have to do with sacrificing and God?
People seem to have an inborn sense that they should worship and sacrifice to God. If you look in the beginning of your Bible in Genesis chapter 4, verses 1 through 7, you will see the story of Cain and Abel. These were the very first people after Adam and Eve and they are already making sacrifices to God. In ancient times, people usually sacrificed animals because, since they didn’t use money yet, animals like cows and sheep represented wealth, plus the shedding of blood represented life and death.
Also, if you look toward the end of your Bible in Saint Paul’s letter to the Romans in Chapter 1 verses 18 to 23 (also see Wisdom 13:1-9 in the middle of the Old Testament), Saint Paul tells us that all people everywhere are searching for God, but since many of them did not know the God of the Bible, they began to try to worship God the best they could. However, this led to a lot of false religions in the world that, even though they may have had some good about them, led them into wrong ideas about God. Some of these false religions went horribly wrong like the parts of Aztec and other civilizations that had human sacrifice and other terrible practices.
The Christian idea about sacrifice came out of sacrifices of the Old Testament which was the beginning of God’s revealing himself to his people. The Catholic Church teaches us that Jesus Christ came to end all these sacrifices which were only kind of image or preparation for his one, true sacrifice. But why did God choose to sacrifice His only son if He loved Him so much? This is the most important question of all.
Ever since the time of Adam and Eve (the parents and representatives of mankind) and the Original Sin (see Genesis, chapter 3) mankind has been separated from God, not only because of our first parent’s sin but because of all the sins committed by every person who ever lived on the earth. God created us to live with him in heaven forever but since none of us ourselves could possibly make reparation for all this sin that separates us from God (since God is infinitely Holy), God in his great mercy and love found a way.
God loved us so much that that is precisely why He chose his own Son to sacrifice himself on our behalf. Since Jesus was fully man (so he could represent us) and fully God (so that he offer such an infinite sacrifice) he was the only one who could do it. That is why we call him our Savior. All that is left for us to do is to place our faith in him and his sacrifice, be baptized, and follow his teachings everyday. That is why we call him Lord. “For God so loved the world that he gave his only Son, so that everyone who believes in him might not perish but might have eternal life.” (John 3:16)
When we go to Mass every Sunday, it is this very same sacrifice of Jesus (not a new one, but the same one) that is being re-presented on the altar under the appearance of bread and wine and which we have the privilege of participating in offering our worship and our daily lives. Just think: we are participating in the greatest sacrifice there ever was!
Sorry this answer is so long, but it is a good and important question and I wanted to give you the best answer I could. Please keep asking those good questions—and I will try to be less long winded!