Allah The Glorious is unlimited in all His Virtues, and we humans are limited in our thinking, so, we, The limited can never include The Unlimited.
‘(Nothing is like Him) Sura 42, Verse 11.
We see the signs of the greatness of Allah through seeing the universe ( We will show them ( human beings) Our signs in the horizons and in their own selves, so that it will be clear for them that Allah is The Truth)( Sura Fossilat, Verse 53).
We believe in Him being The Only Creator, because of what we see and know in this universe, and our faith in Him increases with more knowledge and proper pondering and thinking.
The Hadeeth says: Think about the Creatures of Allah, to know His Greatness.
The Prophet Muhammad (SAWA) told Ali ( AS): No one (really) knows Allah, but myself and you, and no one knows me but only Allah and you, and no one knows you, but only Allah and myself.
Reading the Supplications from Ahlul Bayt (AS) like Du’a al-Sabaah, with understanding, makes our faith stronger.
Seeing and thinking about the creatures of Allah in the sky, earth, sea, oceans, animals, plants, mountains, stars, planets, atoms,galaxies, embryos, genes, human organs and human life, etc makes us in front of The Greatest fact in this existence, which is: No God but Allah.
Thinking about what Allah has created is one of the best worship.
ويتفكرون في خلق السموات والأرض
(They ( the believers) think and ponder on the creation of the skies and earth)Sura Aal Imran, Verse 191.