Nature (Humanity) vs. Nuture (Gospel)

I know I promised to bring information from other sources, but I have been thinking a lot about this, and I am curious of your thoughts on the matter.

Fact #1: Our human nature teaches us to care about ourselves and serve ourselves in any way possible. Not to say that sometimes we in our human nature reach out to another human being to offer assistance especially in times of extreme need (natural disasters. family losses, etc.)

Fact #2: The Nuture, what we can be trained to follow is the Nature of Christ, which is a complete oxymoron to the way of the world. There are countless scripture about not conforming to the way of the world. In my personal opinion, in the top 5 ways that we act like Christ and not the world, is the fact that we should be more concerned about our brother than ourselves. That is true humility, true love, true sacrifice, etc.

Now, here is my question. We know that Fact #1 is bad and Fact #2 is what we should strive to be.

Why do so many of our lives look so much like a polar opposite to Christ and worse than that, if we were to be confronted about it, we have what we think is a strong defense for our actions...

i.e.:
- shopping for ourselves all the time
- gossiping about others knowing it is wrong
- just being a jerk, making people not want to be in your company
- always telling stories about how great we are
- never talking about Christ's life or the things He has done in our life
- thinking that being born in a certain country makes us entitled to certain rights and freedoms, forgetting that human being just like us are daily suffering and we just don't care

this list could go on forever...

Disclaimer: I am NOT saying I am perfect, but can SOMEONE shed some light on this please?