St. Paul, MN
When you're speaking of the differences between men and women there are such a multitude of factors I don't think that a single person could ever pinpoint the difference between the sexes beyond the obvious.
On a biological level, men have an extra chromosome (not gene.) Of course, women have two X genes and men only have one and the tiny Y chromosome. Despite what sounds like a small difference there are obviously many physiological differences that arise from this. Different levels and varieties of hormones within the body, metabolism, and the obvious physical differences of the reproductive organs.
Does this change how we think and view the world? I would be inclined to say yes considering the power of hormones on the body. Testosterone has it's own key personality traits that it induces, most of them maninfest them selves physically. Estrogen and progesterone also have their own influences (and I'm sure there are are more sex based hormones, I'm just forgetting them.)
I don't believe biology is the only key here. It definitely determines your sex, but I'm not sure if it really makes your gender concrete. Environment and the nuture aspect have quite an effect on this. A woman growing up in a very physical, tough life around men might display more "male" character traits while a man living in a domestic society surrounded by women will more than likely display more "female" characteristics.
Spiritually, I don't believe that the same god you speak of created us all. Our universe is full of dualities. Obviously most of the creatures that live on this planet, including us have this duality.
This duality is to me one of the mysteries and wonders of our lives. We are different, and yet we are the same. We're flesh (and spirit, if you are into that) and we have thoughts and we go through life with a slightly different view of things. Through the union sexual and otherwise of male and female we obtain a grander scope of the world and life.
"Knowledge is far superior to Belief, for Belief is the way of the uniformed." - Scott Cunningham