The Object Lesson - Alka Seltzer Rockets
Have you ever had such good news you couldn’t wait to share it with someone? Think about getting engaged to the love of your life, or finding out you are expecting your first child, or you just set a new record on Zelda. Whatever it is that makes you excited, you know the feeling of struggling to keep things held inside. Good news is meant to be shared.
You will need some old school film canisters (https://amzn.to/3dYaYpw) and some Alka-Seltzer tablets (https://amzn.to/3pK8KMT).
Fill the bottles approximately 1/3 of the way with water, then add ½ of an Alka-Seltzer tablet and firmly place the lid back on the canister. Place the canister upside down (lid on the ground), on a hard flat surface. While you are doing this, you can talk about how hard it is to hold good news inside. The pressure builds and builds until we just have to share the secret. After 5-15 seconds, the pressure inside the canister will be enough that it will force the lid off the top and shoot the canister into the air with a loud pop.
The science behind this demonstration is simple. The Alka-Seltzer causes a chemical reaction that turns some of the water into a gas instead of a liquid. The amount of gas takes up a lot more room than it does when it is a liquid. As the gas builds up, it keeps pushing outward trying to make more room. Eventually the lid will pop off so the gas can escape.
Explain that if we really believe the good news about Jesus, we should be so eager to share it that it just pops out of us. The canister is simply not strong enough to hold in the pressure that builds up from the Alka-Seltzer and water, and we, like Jeremiah, Peter, and John, are not able to hold the good news in.
The Bible Connection – Jeremiah, John, & Preaching the Gospel
In Jeremiah 20, Jeremiah has just been beaten for preaching and proclaiming the message God had put in his heart. The implications are clear, he is supposed to stop prophesying or they will continue to punish him. But Jeremiah has a problem. He doesn’t preach because he wants to, he is speaking God’s truth because he can’t stop. In Jeremiah 20:9, it says,
If I say, “I won’t mention Him
or speak any longer in His name,”
His message becomes a fire burning in my heart,
shut up in my bones.
I become tired of holding it in,
and I cannot prevail.
Jeremiah has the word of God so deeply pressed into his heart that he cannot help speaking about. The process of trying to be silent makes him feel like his heart is on fire. He speaks because he has to. In many ways, this reminds us of John and Peter when they are arrested in Acts 4.
Like Jeremiah, Peter and John have been told to stop preaching. Like Jeremiah, the threat is implicit. If you keep talking about Jesus we will keep punishing you. Peter and John respond with words that remind you of Jeremiah in verse 19.
But Peter and John answered them, “Whether it’s right in the sight of God for us to listen to you rather than to God, you decide; for we are unable to stop speaking about what we have seen and heard.”
Peter, John, and Jeremiah all had one thing in common. They were so convinced of who God was and how powerful his message could be, that they could not be silent. They had to tell people God’s message because they couldn’t contain it.
Other Scriptures and Topics to Explore
This object lesson could be used to talk about several different topics. There are a lot of emotions and words that come “popping” out of. Some of these are positive and some are negative.
Anger – Ephesians 4:26-27
When the Bible tells us not to sin in our anger, it is warning us that we must deal with our anger before we “blow our lid.” Anger, if it is not dealt with, can lead us to slander, violence, and even murder. We must release our anger or it overflow.
Thanksgiving and Praise – Psalms 119:17
When we recognize all the good God has done for us, our natural response should be praise. A true understanding of God’s goodness and God’s love should cause an overflow of thanksgiving.
Taming Our Tongue – James 3:2-12
Some of us speak like the Alka-Seltzer rocket. We let anger, jealousy, and pride build up inside us until we explode on the people around us. James tells us to learn to control our tongue so it does not destroy the lives of the people around us.