One day, a man who did not believe in the existence of God the Exalted came to one of the caliphs. The man said confidently, “I do not find anyone to convince me of the existence of a god, and I challenge the greatest scholar you have, and I am confident of victory over him.” The caliph remained silent for a while and said to himself, “If I order him to be killed, people will say that I was unable to face him with evidence.” Then he called his minister to summon Imam Abu Hanifa for him.
When he came to them, the caliph asked him to convince this man of the existence of God the Exalted. Imam Abu Hanifa said to him, “I will prove that to you, but I ask your permission to finish a necessary matter in the neighboring village, then I will return quickly.” The caliph gave him permission, but he was greatly delayed. The atheist felt arrogance and pride and said to the caliph, “I ask your permission to leave, for Abu Hanifa has fled because he is unable to convince me at this moment.” Imam Abu Hanifa returned and apologized for the delay.
Then he told them that he found a river on his way and did not find a boat, so he sat waiting for a boat to arrive. His waiting was long, then suddenly the Imam saw a wondrous thing. He saw wood gathering and nails standing on the wood, and a hammer appeared and began striking the nails until he saw before him a well-made boat. He rode it and arrived. The atheist began to laugh and said, “This speech is said only by a madman, and no one believes it. How can nails and boards fly in the air and gather on the water and form a boat without anyone making it?”
Here Imam Abu Hanifa smiled and said, “If the existence of a small boat without a maker is not believed by reason, does reason believe that this universe with all that is in it of earth and sky, sun and moon, existed by itself without a creator creating it?” The atheist was stunned, then said to him, “You are right. There must be a creator for this universe who created it and organized it, and He is God.”