Today many Muslims are believers of Allah just because they are born in a Muslim family, previously Muslims believed in Allah because of the strong evidences of Islam and were capable of countering the arguments of atheists and agnostics through solid proofs.
Once Imam Abu Hanifa was asked by an atheist that what’s the proof of God? He replied forget it! I’m thinking about a great ship, which contains many goods and is travelling in the sea without any captain or crew and is successfully going through the sea. It stops at the location that it should stop and is going perfectly into its correct direction.
The atheist said what a silly though it is, how anyone with any intellect can believe this. Then Imam Abu Hanifa said I feel sorry for you as you cannot imagine a ship running without a captain yet you think the world world is working perfectly without a Creator and master?