On the day of Arafa, the 9th of Dhul-Hijja, God (Allah) made the descendants of Adam (the souls of all mankind that would be created later) witness that he is our God. However, God sent messengers to remind the people of him.
7:172 Al-A'raaf
وَإِذْ أَخَذَ رَبُّكَ مِنْ بَنِي آدَمَ مِنْ ظُهُورِهِمْ ذُرِّيَّتَهُمْ وَأَشْهَدَهُمْ عَلَىٰ أَنْفُسِهِمْ أَلَسْتُ بِرَبِّكُمْ ۖ قَالُوا بَلَىٰ ۛ شَهِدْنَا ۛ أَنْ تَقُولُوا يَوْمَ الْقِيَامَةِ إِنَّا كُنَّا عَنْ هَٰذَا غَافِلِينَ
And [mention] when your Lord took from the children of Adam - from their loins - their descendants and made them testify of themselves, [saying to them], "Am I not your Lord?" They said, "Yes, we have testified." [This] - lest you should say on the day of Resurrection, "Indeed, we were of this unaware."
7:173 Al-A'raaf
أَوْ تَقُولُوا إِنَّمَا أَشْرَكَ آبَاؤُنَا مِنْ قَبْلُ وَكُنَّا ذُرِّيَّةً مِنْ بَعْدِهِمْ ۖ أَفَتُهْلِكُنَا بِمَا فَعَلَ الْمُبْطِلُونَ
Or [lest] you say, "It was only that our fathers associated [others in worship] with Allah before, and we were but descendants after them. Then would You destroy us for what the falsifiers have done?"
We have also witnessed our lives before the creation and that explains why we remember people at the moment we meet them or things before they happen or at the moment they happen; the déjà vu or memory clashes.
Remember God, you witnessed that he is your creator.
God (Allah) exists.
