Just because our small brains limited to what we found on this one small planet cant explain the grand scheme of things with 100% percent certainty, doesnt mean an eternal creator made it all.
You only say this universe was "created by clear design", because you end of the perspective it all fits so perfectly, it all plays together, right? Of course it does, because me and you, we are the result of it all. Doesnt mean someone designed it.
It all fits so well, because everything is the direct result of the steps before it. So that in the end we happened to exist.
I am not saying I know it all or so, I just say that concluding that god made it ll because we dont know how it all happened is stupid.
So you, without an answer, and telling me I need ro live differently. Why? This is my life and I have my own experiences to know how real God is.
We have one book that speaks to all of this, free from contradiction, speaks to history, events today, and future events coming (previous future events already happening and have happened today), touches base on a historical figure that did exist (Jesus), verifiable evidence and about a God who tends to his faithful sheep.
Hebrews 11:1 ("Now faith is the assurance of things hoped for, the conviction of things not seen")
Proverbs 3:5-6 ("Trust in the LORD with all your heart, and do not lean on your own understanding"). This verse in particular counters your argument about not being able to lean on your own understanding. We have scientific advances that lean towards the understanding that we have a soul and our universe is by design. Any change in our worldly design effects everything at a catastrophic level.