I know that gravity exists, even though I don’t know what it looks like. I cannot smell it, I can’t touch it, I cannot feel it.
But I know it exists because it has a strong attractive force on anything and bring it down on the center of this Earth on a bigger object. I know it exists by inference.
We can make all of this kind of our reality, observation, deductions inferences. That’s what we do maths.
So what we are saying is when it comes to reality of our existence and our Creator’s existence, we need to be sincere.
The Quran like telling us the purpose of our life here, telling us what’s going to happen after death, telling us what awaits for us, whether heaven or hell.
So whatever we do which pleases God in accordance to the reasons He’s created us and we follow the command and avoid His prohibitions, this is worship.
In the Quran, God tells us this is one chance. Don’t miss this chance to save yourself from the hellfire.