Science Experiment: Jesus Washes Our Sins Away

Science Experiment Jesus Washes Our Sins Away


Last year in one of our Sunday School classes, one of the teachers showed us a demonstration very similar to this one. Not only did I think it was amazing from a science perspective, I also thought it was perfect for demonstrating the work of Jesus in our lives. After scouring the internet, I found this tutorial and purchased the necessary supplies…and then forgot about it until nearly a year later. :)


The experiment is simply a chemical reaction…but the demonstration is meant to show in a visual way what happens internally when we accept Jesus into our lives.


Science Experiment:  Jesus Washes Our Sins Away



This object lesson is perfect for demonstrating the power of Jesus in our lives. All of us sin and we are tainted beyond repair, even when we try ourselves to fight off the “sin that so easily entangles.” It is only when we allow Jesus to come into our lives that we are cleansed and purified. Once Jesus lives in us, sin can no longer tarnish us in the eyes of God. The blood that Jesus shed on the cross washes us white as snow.


PLEASE NOTE:  There are dangerous chemicals involved in this demonstration, so please use extreme caution and make sure to read the labels on each of the chemicals involved before attempting this at home (don’t let any of the chemicals come in contact with your skin, eyes, or be ingested). Do not let young children help with this demonstration.


Here’s what you’ll need for this demonstration:

1 glass jar
Straw Dispenser
Household Ammonia (found in the cleaning aisle)
White Vinegar
Bottle of Phenolphthalein (I ordered ours on Amazon)
Sticky-back Craft Foam in any color

Jesus Washes Away Our Sins Science Experiment



Science Experiment: Jesus Washes Our Sins Away

1. Cut out 2 identical cross shapes from your sticky-backed craft foam.


Science Experiment: Jesus Washes Our Sins Away

2. Peel off the paper backing from the craft foam and stick the two sides together on the pole of the straw dispenser.


Science Experiment: Jesus Washes Our Sins Away

3. Fill the bottom of the straw dispenser with white vinegar.


Science Experiment: Jesus Washes Our Sins Away

4. Fill your straw dispenser about halfway with water and then add a squirt (or 5-6 drops) of your phenolphthalein.

Not pictured:  Fill your other glass jar about 1/3 with water and add a splash of ammonia.


Science Experiment: Jesus Washes Our Sins Away

5. Use return address labels to label each jar:  the jar with ammonia and water “sin” and the jar with phenolphthalein and water “you”.


Science Experiment: Jesus Washes Our Sins Away

For the demonstration:  Pour the “sin” into the “you” jar and it will turn pink. Pour some of the pink back into the sin jar (in preparation for the next step).


Science Experiment: Jesus Washes Our Sins Away

Carefully place the straw dispenser lid (with the vinegar in the bottom) into the “you” jar and watch as it changes back to clear.


Science Experiment: Jesus Washes Our Sins Away

Attempt to pour sin into the “you” bottle with the cross still in it and it will change to clear, representing that sin can no longer taint us in the eyes of God…Jesus’ life was a sacrifice that cleanses us once and for all.



“But if we walk in the light, as he is in the light, we have fellowship with one another, and the blood of Jesus, his Son, purifies us from all sin.” -1 John 1:7



Check out more awesome Sunday School ideas here.



The Science Behind It:  Phenolphthalein is an acid/base indicator that turns pink in the presence of bases. Ammonia is a base. When the ammonia and phenolphthalein mix, it creates a chemical reaction that turns the liquid pink. The vinegar in the base of the straw dispenser acts as an acid neutralizer and neutralizes the reaction, turning it clear again.




    1. I’m not trying to prove anything. It is simply an external demonstration of the internal work that happens when we accept Jesus into our lives.

      The experiment isn’t meant to be scientific…just a demonstration for kids and adults alike. I’m sorry this isn’t a post that resonated with you. Have a great day!

      1. This is FANTASTIC!! The concept of sin in our heart/soul making it filthy before a holy God is a difficult one for kiddos to grasp & this visual is perfect! The idea of something (our souls) being made clean by Christ is clearly illustrated here in way that will facilitate a question & answer time where the gospel can be explained again. Thank you for posting this!

      2. It is literally titled “Science Experiment”. This is a religious demonstration. A science experiment has set steps to follow called the Scientific Method.

        1. You are right, it should have been titled “demonstration” or “visual representation”. However, it does include a description of the science behind the actual experiment, which I also explained to my children. They know the illustration itself wasn’t supernatural, just a visual for the internal work that happens inside of us when we accept Jesus. Sort of like a modern day parable. :)

    2. Thankyou.
      We can se this in Sweden too.
      As the Gospel….it’s spread in the world.
      Thanks for your god heart!

  1. Well, what a load of tripe. When I see this kind of stuff, I often think of the quote that goes; intelligence is limited, but stupidity is boundless!
    Is is your obligation to teach your children to think, reason, and question everything, and not fill there fertile minds with such nonsense. Teach them facts not faith, reason not religion, and science not stupidity. The world is a wonderful place and could be better without the kind of garbage you have posted.

    1. I’m sorry you found this post to be so offensive. My children are learning to think, reason, and question the world around them daily. They are smart and inquisitive. We are also teaching them that everything in our lives is framed through our relationship with God. The two are not mutually exclusive. We are not perfect parents by any stretch of the imagination and we fail daily, but we are doing our best to point them to the One who is perfect all the time.

      I know this post obviously won’t change your mind about what you label as “garbage” and you certainly have the right to express your opinion. And surprisingly, I don’t mind being called a fool. :)

      “But God chose what is foolish in the world to shame the wise; God chose what is weak in the world to shame the strong” -1 Corinthians 1:27

      1. Jesus is the only way!!! I pray that all who don’t believe will have a change of heart and accept Jesus as their savior.

  2. Probably you should call this NOT A SCIENCE EXPERIMENT: Pretending there is a need to wash away an imaginary friend from your life. Don’t be sorry you offended people, we get it a lot…its just so hard to grapple with people who believe in things like Santa Claus, the Tooth Fairy, and Jesus. We love you unconditionally and accept you in our hearts, but we’ve established a lot of science over the years and we’re trying to go forwards, not backwards in our established, objective observations of the world. Things like this tend to confuse people into thinking that something supernatural is occurring, when it is clearly not. Enjoy the SCIENCE that made your trick look magical and not attribute it to your lord and saviour, jesus.

    1. You are right, it would more accurately be described as a visual representation or demonstration rather than “experiment”. Although, I did a “two for one” with my kids, explaining the science behind the reaction while also telling them that it is a great visual representation of the internal work that Jesus does inside of each of us when we choose to accept him. They did not think it was “supernatural” in the least…they helped me and saw the chemicals we used. But it does have a “wow” factor that causes us to think, which is what the post is intended for. I think of it as a modern-day parable. Jesus used agricultural metaphors to reach the people in his day, why can’t we use chemical reactions?

      I really appreciate your respectful comment (minus the imaginary friend part, that was a bit disrespectful), even though you disagree with me and my beliefs. Jesus is truly the rock of my life–I can not and will not ever deny his transforming power inside of me. I am NOT sorry for offending people, I am sorry that this post OFFENDS someone. There is a difference–I will never apologize for sharing my beliefs, but I am sorry that people take such offense at those beliefs. It is my life’s goal is to help my children come to know Him while simultaneously showing His love to those around me. Have a wonderful day!

  3. Thank you Janae – this is great and we will be using in our Sunday School lesson this next term to represent as you say the internal work that Jesus does in our lives. I fail to understand some of the previous commentors – if you don’t agree with a belief system don’t enter articles and criticize and belittle other people because of your insecurities and disbelief. I hope you are not affected by their negativity and continue doing such a great job!!! Lots of love!!! Debbie and Shannon

  4. This is a very helpful demonstration.

    Is it possible to start with the “sin” jar already pink, so you do not need to pour some water back into the sin jar? I think it would help with the flow of the presentation. Because, I did it once already and kids asked, “Why did you pour back into sin?”

    1. I saw someone perform this demonstration on youtube and they poured the pink back and forth a couple of times stating we try to rid ourselves of sin without any success. I thought that made it flow better.

  5. Jenae, thank you so much for your post. I thoroughly enjoyed it and plan to use it in our Sunday School. Keep up your strong witness for our Lord and Savior Jesus Christ. I applaud your testimony in Him! I am one who “gets it”! Praise Him!

  6. I’m reading this, this morning, and love it. I don’t mind being labeled a fool, or any other type of “label “that someone may feel capable of listing on us, but I think it is really neat. thank you, keep up the good work. God bless!
    lew combs
    Wilder, KY.

  7. We did this at Awana’s last night. The kids — and the helpers — loved it. Such a great visual!!! Thank you!

  8. Good Afternoon Ms. As a science educator and a Sunday school teacher. I found this activity relevant to the theme. Using science activity (i.e experiments) in a bible story, it helps the children visualize or imagine why Jesus sacrifice himself for us. I am happy that people like you do their best to share Jesus to everyone and creates ideas and crafts that engage children to learn more about God.

    P.S. I hope that you do not listen to the negative comments here. Keep going coz’ you are a blessing to every children of God.

  9. Hi,
    I am a student teacher on my final placement in a primary school setting. I just wanted to thank you so much for this amazing idea. I believe it will really help my class in understanding why Jesus died for us. I am awaiting an inspection, and I believe this will absolutely knock the socks off any inspector who comes into my classroom!
    I don’t understand why you have received so many negative comments. Personally, I am not a believer, but I still have to teach about God and Jesus. Other people’s opinions and beliefs do not influence my life, I would not get so angry at someone for sharing clever ways to portray their beliefs!
    Thank you again, you have really saved my bacon with this!

  10. Love this Object Lesson! Using this on Sunday for our Children’s church as we talk about sin and forgiveness!! Thank you!

  11. I loved this visual. SO creative and a great option to another similar demo with colored water and bleach that I have done over the years. I think your response to negativity was classy and loving! Great job!

  12. Thank you for sharing this experiment and WONDERFUL OBJECT LESSON! I can’t wait to try this in school! I think it’s great for adults as well! Thanks again! (and don’t worry about the haters…pray for them)

  13. This is a fantastic idea! Perfect for my Children’s Church kids. We are studying the life of Jesus now and this will fit perfectly into the lesson. Thanks so much for sharing.

  14. Thank you for sharing your post. This is a wonderful demonstration for adults and children as well to grasp the concept of how we can become more Christlike through repentance.

  15. I have been using this object lesson for the past 3 years on Easter Sunday. This is my absolute favorite illustration to use! There is something so powerful about such a simple object lesson. I truly appreciate you sharing this. I LOVE when the Bible comes alive to my students and this does such a great job in aiding with that. Thank you! Thank you! Thankyou!

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