Did I tell you about the time Zoë almost spilled the precious blood of Jesus? She was about 6 or 7 months old, and I took her up for communion with me - just like every other time. Only she had become really grabby, and I forgot all about this new phase of hers. I held her on my left hip while holding the chalice in my right hand. As I was handing the chalice back to the server, she grabbed the rim of the cup and pulled it towards her. I could see the precious blood within centimeters of splashing out. I was so thankful nothing was spilled!
Oh my goodness! Our Lord Jesus shed his blood for us, and my sweet baby almost knocked it to the ground! What if she had spilled it?! Would they wipe it up with a towel? BUT IT'S JESUS' BLOOD! You can't just wipe it up with a towel, can you? Surely it wouldn't be the first time someone had spilled the Blood of Jesus in the last 2,000 years!
Well, as it turns out, there's protocol for this type of thing. So it's probably happened before. Because we've been receiving the blood of Christ for 2,000 years, and babies have been grabbing and pulling at things for even longer.
So here's a quick answer from Catholic Answers to the question, "What is the correct thing to do when the precious blood is spilled during distribution of the Eucharist?" Then read here to answer the related question, "Can you pour out the precious blood?"
And since a person can receive only the host and not the cup and have received the full "body and blood, soul and divinity of Christ", I'll be passing by the chalice the next time I have Zoë on my hip. It'll relieve a little anxiety for me at least.
If this all sounds crazy foreign to you - the way we think of the bread and the wine as being sacred and truly the Body and Blood of Jesus, read John 6. Read all of it. The entire chapter. A lot of people try to explain away John 6 as just being symbolic. You can read commentary explaining why John 6 doesn't mean what John 6 says. I mean, people do mental backwards somersaults to explain it away. The Bible warns us about men who make the Word of God void, "Thus you nullify the word of God by your tradition that you have handed down. And you do many things like that." (Mark 7:13 NIV) Before you read John 6 ask God to reveal the truth of His Word to you. He will.
As some more icing on the cake, here is a little 7-minute video to illustrate how AMAZING WONDERFUL the Eucharist is and what we believe the Bible says about the Body and Blood of Jesus: