"A Potato That Wasn't A Christian" is a 1960 pamphlet that's not as funny as it sounds

A Potato Wasn't A Christian: A Story For Children (not as Funny as it Sounds) is a 3-page Evangelical pamphlet published by the Pilgrim Tract Society in 1960 that, uhh, well, is exactly as the title suggests. Here's the actual not-as-funny-as-it-sounds story, via Internet Archive and Christian Nightmares:

Well, you see it happened this way. The huckster (peddler) had been selling potatoes on the street and mother had bought a bushel of beautiful and fine-looking potatoes and put them away in the basement of the house. A little boy lived in this house, one of a family of four children. He did not go to school: he helped mother. Everyday he went down and got the potatoes and brought them to mother. Then he would watch her pare them and prepare them for cooking. One day she cut a big potato right through the middle and it was black and rotten; and he said, "Mother that potato is not a Christian, is it?" Mother said "Why what do you mean? Of course potatoes are not Christians-only people." "It isn't a Christian, Mother" he said, "Because it is bad at its heard and rotten inside."

You see when his mother cut the potato and found it bad in the center, the little boy remembered this his mother had told him; that those who are not Christians had old hearts that were bad and rotten with sin on the inside. She had told him how nice they could look on the outside and yet be so very bad on the inside. So when he saw the rotten potato he thought of what his Mother had said and told her "That potato is not a Christian.

A Christian is a person who has a new heart. God never changes the old heart: for the bible says it is desperately wicked and cannot be cured. God sais that it is so deceitful above all things," that none can know it.

You cannot always tell when a potato is bad at the heart, and it often looks fair and fine on the outside; but God knows what is in the heart. If you want to see how bad it is in the heart of a man who is not a Christian, then we will let the knife of God's Word do for the human heart just what the knife did to the potato. Read Mark 7:21-23 and you will see the bad in the heart. The Christian has a new heart. There is no way to fix up the old heart. The new heart is created. It is a clean heart. Therefore the Psalmist when he had gone wrong, prayed "Create in me a clean heart." Now you understand what the little fellow meant when he said "that potato is not a Christian."After this when you cut an apple or potato or crack a nut and find it bad on the inside, you can think of the same thing and say "That potato is not a Christian;" for it is a good illustration of corruption (filthiness) of the human heart. A worm gets into the heart of a potato and rots it. It was the serpent of sin that got into the heart of man and made it bad.

The Blood of Jesus Christ, his Son, cleanses us from all sin. (1st Jn 1:7)
Remember now thy creator in the days of thy youth." Ecclesiastes 12:1

Jesus loves you! Pray to Jesus now and ask Him to come into your heart to live. He wants you to have a clean heart and not be rotten on the inside.

Well, folks. There you have it, I guess.