Which Square is Darker?

Sold in packs of 100 (eg 5 packs = 500 tracts)

This tract springboards into the gospel using an illusion where two squares are presented as different in shading . . . or are they?

After the illusion is presented, the following text is written: 

Try and think of other things that deceive the human eye. Here are some examples: 1. The mirage of what looks like "water" on the road on a hot day. 2. The sun rising and setting. The earth turns, giving our senses the impression that the sun is moving. 3. Then there is the illusion that the sky is blue, when it actually has no color. These sort of sensory perceptions don't really matter, because they don't have any serious repercussions. However, there is one illusion that is a very serious deception. It's the mistake that people make when they think that they get into Heaven on the basis of their own goodness or by their own good works. Do you believe that? If you were mistaken, wouldn't you like to be told, or would you prefer to stay deceived when it comes to such an incredibly important matter? 

Please, go through this short checklist of the Ten Commandments to see how you will do on Judgment Day and if you are good enough to get into Heaven: Have you ever told a lie? Have you stolen anything (irrespective of its value). Have you used God's name in vain? Jesus said, "Whoever looks at a woman to lust for her has already committed adultery with her in his heart." Have you looked with lust? Will you be innocent or guilty on Judgment Day? If you have done those things, God sees you as a lying, thieving, blasphemous, adulterer at heart. The Bible warns that if you are guilty on that Day you will justly end up in Hell. Yet, God made a way for humanity to be forgiven. He sent His Son to suffer and die on the cross for guilty sinners. We broke God's Law, but Jesus paid our fine. That means God can legally dismiss our case. He can commute our death sentence and let us live: "For God so loved the world that He gave His only son, that whoever believes in Him should not perish but have everlasting life." Jesus then rose from the dead and defeated death. 

Please, repent (turn from sin) today and trust alone in Jesus. You will never regret it. Then read your Bible daily and obey it (see John 14:21). We can only get to Heaven on the basis of God's righteousness given to us in Christ, and as a free gift of God's grace (see Ephesians 2:8-9). Thank you for reading this tract.