Why can't I believe in God AND evolution?
I do not have to believe that Adam and Eve were the first man and woman in order to believe in God.
Everyone who believes in God is not a Christian, and not even all Christians believe that Adam and Eve were the first man and woman.
You can (and do) believe in things that other people do not. There is no law against that.
You can believe that the world was created by an evil spirit (the way it is). That will be more believable.
Why you believe so is another matter. It depends on the intelligence of the person.
Ignorant people believe in what scammers say.
Of course, who were the first man and woman lies in a very hazy area.
It was a very gradual transition from ancestors of chimps to humans over 7 million years.
Homo habilis skull and reconstruction of the face.
Click to enlarge