Nima,
I agree with the point Mary made that we need to recognize our God created us and then dedicate the good works we do in life to Him and His glory. I also agree with Community that people get caught up in fearing God rather than pleasing him. Taqwa is Arabic which in short means that we love Allah, SWT, so much that we fear displeasing Him because of this love.
It is a love of our Creator, who is Goodness and Mercy and Justice and Eternity, who is neither male nor female, and has no beginning nor end.
I too feel that it would be harsh and unjust to create people just to punish us even though we do good works and have good, kind souls throughout our lives. Some people feel that to be Muslim you have to follow the rules established called the Shariah and follow one of so called four schools of thought. But I don't.
We have basic, simple guidelines in the Quran that guide us. And I personally, possibly to the shock of everyone here, do not believe many of the things literally as I am not a desert bedoin, and my life is very different than the lives of the women during those times. But the parables set clear guidelines for me to follow also.
I don't look at sin as something against God as much as it is against my own soul. These guidelines God made for us are merely things that will help us and our communities in our lives here on earth. Just as traffic signals are there to prevent accidents, many of the Islaamic rules that we follow are there to prevent personal depression and social dysfunction. God loves us and does not seek to punish us as a harsh taskmaster to a slave. He guides us and protects us from the harms inherent in this world, if only we would listen and keep listening!