If every effect has to have a cause, there can be no first cause or first effect.
We know for certain that there are effects. I throw sand in your eye ... you produce tears and suffer from pain and discomfort. Effect? Your discomfort. Cause? Me throwing sand. Go backwards in time, and there was a cause for every effect.
But you and the other atheists or non-believers would have me believe the following:
1) Billions and billions and billions and billions of years ago ... there was nothing. A complete and total void of pure nothingness.
2) Then **poof** for no apparent reason ... gases just showed up out of nowhere. Pure chance.
3) More billions of years go by when all of a sudden **poof** matter formed for no apparent reason. It just showed up by pure chance.
4) More billions and billions of years go by (and you guessed it) **poof** goo formed on this matter that was floating around in voidsville.
5) A few more billions of years go by when, **poof** some a single-celled form of life just appeared for no apparent reason. Just by pure happenstance.
6) We still aren't sure if a food source "poofed** into existence before the life form **poofed** into existed or if the food source **poofed* as an afterthought.
7) Now this brand new life form was somehow able to reproduce even though it's sexual partner had not **poofed** yet. That is, unless male and female life forms **poofed** into existence simultaneously. I'll leave that conundrum to the experts who "KNOW" a lot more about those things than mere, common men.
8) The new life forms also had no eyesight. But after somehow surviving on the food source that **poof** came into existence ... it somehow formed an early version of an eye. It couldn't see yet, but billions and billions of year would surely solve that problem. And **poof** time did exactly that. The life form formed eyes by some non-miracle.
One MUST have a ton of faith to believe that everything we see in the universe occurred by a series of billions of mistakes, happenstances, and **poofs**.