God's Invisible Ink

God's Invisible Ink


Ye are our epistle written . . , known and read of all men (II Corinthians 3:2). But Jesus . . . wrote on the ground  (John 8:6).

Purpose of the Illustration

  1. To show how God is able to give a spiritual mes­sage to a Christian—a message which is invisible and unintelligible to the world.

  2. To point out that it requires a spiritually warm heart to receive the message which God writes in His invisible ink.


  1. A sheet or sheets of paper—any kind will do— preferably a large sheet.

  2. An iron pen, stylus or an ordinary pen with the usual point.

  3. A rack which you can hold up, and on which you can write. It is better to let the audience see you write the message.

  4. A cup with a handle, or a thick mug.


  1. Sulphuric acid.

  2. Ordinary water.

Method of Procedure

  1. Measure ten parts of water into the cup or glass container with handle. (The chemical reaction creates heat, hence an ordinary glass is not safe to use.)

  2. Add one part sulphuric acid to the water. Pour the acid slowly down the side of the container rather than dropping it onto the surface of the water, which eliminates the danger of burns from the steaming and splashing acid. You may use any measure, but keep the right proportion. Since you will need only a small amount of the liquid, it is best to make only a few spoonfuls at a time.

  3. Place your paper on the writing rack so that everyone in the audience can see what you are doing.

  4. Dip your pen into the chemical solution.

  5. Write your message. If you choose, you may talk and write only a few words at a time. This will create and hold suspense.

  6. Warm the sheet of paper, after the solution has dried and become invisible, over a small flame or by holding it near a light bulb. Warm the paper sufficiently to bring out your written message.

  7. Display the reproduced message, written in the invisible ink you made, to the audience, or pass the copy around so that the people, especially the children, may hold it.

Chemical Reactions

  1. The sulphuric acid in the water generates heat, but do not be afraid of it.

  2. The solution used in writing on the paper soon dries and leaves your message invisible.

  3. The heat brings out the coloring of the invisible diluted sulphuric acid, and therefore the message.


  1. Add the acid to the water, and never the water to the acid, for this often creates a violent reaction, and the solution might get on your hands or clothes.

  2. Be careful to protect the table or the pulpit, your clothes and also your hands against this possible reaction.

  3. Use a container with a handle or a thick mug because the generated heat makes the container quite hot.

  4. Be careful to maintain the suspense throughout your talk. Do not warm the paper until near the close of your address. You may heighten the suspense by writing several messages upon various pieces of paper, or by having members of the audience come to the platform and write messages.

During war times great use is made of codes in sending messages. Enemy countries place their spies in each other's ranks, and when vital facts are discovered, they are sent out of the country through the use of ingenious codes. Spies have been known to have messages in code, designs of inventions, secret formulas for explosives, high octane gases, etc., written on their own skin with invisible inks which can be brought to light only through the use of the proper chemical.

Set out your equipment. God has methods of transmitting His truths to the human race, but He uses only certain methods which one not attuned to Him is unable to understand or decode. The wisdom of God is foolishness to the world.

I am going to show you how you can write a message upon ordinary paper with a solution that can be read only by one who knows the process used—begin to make your invisible ink. By means of this acid, plain sulphuric acid and ordinary water, I am going to make an ink. When you write with this ink you cannot read or see the message unless you know how to develop it, or bring it out. Once you know how to do it, the secret becomes very simple indeed, and anyone can read the writing.

See this large sheet of paper? Display the paper. And here is an ordinary pen. Show the pen. Now watch me as I write. The writing is plain enough, and the letters I am using are ordinary English letters that anyone ought to be able to read.

Pass the first paper to the audience when the solution is dry. Did you say there is no writing on the paper? But you saw me writing, did you not? The trouble is you are not acquainted with the secret of the writing. If you knew it, then you could tell me exactly what I have written. Write several more messages on paper and pass them to the audience.

Just so God has written or given His messages to individuals who were able to interpret or receive them. These people were in tune with God and hence when He spoke they understood His words. The Bible was written this way.

Call for several sheets to be returned to the platform, or have children come to the platform to investigate the sheets of paper and report to the audience that there is no writing on the paper. This adds to the interest.

There are some people so attuned to God that when He speaks they can hear. The boy Samuel was such a person. You remember, children, the old prophet Eli could not receive the message that the Almighty had for him, so God spoke to Samuel, who heard His voice and interpreted the message to Eli. Thus we can so live that the writing of God, the words of God, His voice, the imprint He makes on our hearts can be read.

The ink or message is invisible to those who are not in accord with Him. Now, I am going to take the paper and show you how the message may be brought to light and made visible. All that is required for this particular message written with the invisible ink I made here on the platform is simply heat or warmth.

Use a match, or put the paper close to a high-powered light bulb. While you are warming the paper call for several from the audience to come to the platform to watch the results.

Watch carefully, for I am decoding or developing the invisible ink message. Hand the sheet to someone new and ask what they see. I am going to ask this person to read the message. God Is Love is a good message, short and significant. When the first one is read, you can call for others, and let them serve as texts for a few words of discussion.

Why was it you could not read the message before I applied the heat to the paper? That is right—it took heat to bring out the letters. So in life, many people miss the glory of hearing from God and reading His letters written on their hearts because they are too cold and calculating. They are too far away from the Source of life and spiritual joy. They are spiritually cold, dead in trespasses and sins.

To hear from God requires a spiritually warmed heart, a life which has been touched by Christ and filled with His power and glory. Persons who meet these requirements can hear from God while others, cold in their spiritual lives, are dead to His voice.

Stephen Grellet was one of these warm-hearted Christians to whom God often spoke. Once while he was praying, his heart was suddenly impressed—divine heat was applied to the invisible message on his heart—that he ought to go to the northwest woods to a certain camp and preach. He was obedient to the Spirit, and went only to find the camp abandoned.

Said the Spirit, "Did I not tell you to preach?" Replied Stephen, "But there is no one to hear me." "Preach," said the Spirit.

And Stephen stood up, took a text and preached a powerful sermon. When he finished, he called for mourners to come forward and be saved. Then, although no one was present, he dismissed the invisible congregation.

"Foolish," you exclaim.

Not so; years later in an American city Stephen was walking along with the crowd when a man touched him on the shoulder, and said, "Are you not the preacher that came to a logging camp in the northwest and preached a sermon to a vacant lumber shed?"

When Stephen said he was that man, the stranger continued, "I was on the other side of the lumber pile, and at first thought you were a fool, but the more you preached, the more convicted I became, until at last when you called mourners, I knelt and the Lord saved me. Later He called me to preach and during the past years I have won thousands to Christ."

What was it? A miracle? No, only the results of a warm-hearted Christian obeying God's voice—a Christian to whom God could speak, or on the tables of whose heart He could write a message in ink invisible to others. Stephen's spiritual warmth enabled him to read and interpret the message.

We all can so live that God will speak and we will understand His will. It is no miracle, only the result of warm-hearted Christian living, when one dwells under the shadow of the Almighty and abides where He is.

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