I just don't get it

[Lek]

And what god is that? Your religion, like all other religions, don't just have problem with science but all other religions too. Christians think that the only route to salvation is accepting Jesus as one’s savior. If you’re a Muslim, that doctrine will send you straight to hell. The Quran also claims that Jesus was slain but not crucified, with an impostor dying on the cross. Jews, of course, don’t see Jesus as the Messiah at all.
Hinduism has many gods. Jehovah’s Witnesses think that precisely 144,000 of them will make it to heaven, while the others who are saved will inhabit a paradise on Earth. In contrast, Laestadianism, a conservative branch of Lutheranism, considers itself the only true faith: only its roughly sixty thousand adherents are eligible for salvation, with the billions of others on Earth doomed to eternal torment.

Black Muslims believe that whites are a race of devils, created less than seven thousand years ago from selective breeding by a mad black scientist named Yakub. And, of course, there is Xenu and his hydrogen bombs. Add to these all the conflicting doctrines and equally conflicting moral codes that differ in how one should treat women, gays, sex before or outside of marriage, criminals, animals, and so on. They can’t all be right.

Your argument doesn't hold water.  The God I'm speaking of is the one true God who has revealed himself to numerous billions over the history of mankind.  If God has revealed himself to a person, then that person knows the one God.  There is only one truth, but there are many beliefs and opinions among believers..  Let me give an analogy.  The truth that we exist here on this planet has been given to everyone in this forum.  We all know that truth.  Some us think that this world we live in was created by God from nothing.  Some think it may have always existed from eternity.  Others might think it just popped into existence from nothing all by itself.  The truth that we are here has been revealed to us all, but we don't all have the same beliefs about how we arrived here.  Most of us probably agree that there was an evolutionary process that occurred, but details about how how it occurred are understood differently, even among fellow atheists.  But, yet we agree that this process took place.  There is only one truth concerning how these processes took place, but we don't all share the same opinion of what that truth is.