Narrated Abu Huraira: Allah's Apostle said, "Satan comes to one of you and says, 'who created so-and-so?’ Till he says, 'Who has created your Lord?' So, when he inspires such a question, one should seek refuge with Allah and give up such thoughts"( Bokhari).
This hadith reveals that Satan Iblis whispers to a believer about Allah’s existence saying that “who has created God? So that he may cast doubt on him and make him speechless about Allah-Almighty as being a Creator of this universe. And also he may mislead him and causes him not to act upon the teachings of Islam.
So in this whisper touches him, the believers must seek refuge in Allah and read: اعوذ باللہ من الشیطٰن الرجیم and put away this whispering.
As regards that how can one recognize God, so, a man should consider in various signs i.e. signs in his soul and signs in the horizon.
As regards the signs of Allah’s existence in the human’s soul, so he should think about himself that where he come from and how did he was created? So he was a thickened fluid in the womb of mother at first, and then he is delivered in this world and then by and by he becomes young and old and then he embraces the death,
this is the reality of human being. A hadith reveals that من عرف نفسہ فقد عرف ربہ “who has recognized himself i.e. his reality, then he can recognize Almighty.”
As regards the horizontal signs, so man should consider over the sky, Moon, Sun, Stars, Planets Galaxies and their movements into a fixed circle. Because they are Billions of trillions, but they do not collide with each other at all.
The holy Qur’an reveals,” And He it is Who created the night and the day, and the sun and the moon. They float, each in an orbit. ﴾ Al-Anbiya :33﴿
Those who want to recognizes Allah Almighty sincerely and strive for it, then they can find Him surely as the holy Qur’an reveals,”
But as for those who strive hard in Our cause -We shall most certainly guide them onto paths that lead unto Us: for, behold, God is indeed with the doers of good” (Al-'Ankabut 29:69).
Only Discussion for discussion is not useful in this way.