Question : Is it due to a sin that we are born??
Is it a sin if we spend more time on spirituality than to read our daily books suggested by the authorities?
and what is karma then??
Is the bondage of karma due to sin??
Answer : It is not due to sin that we are born. The whole world is a manifestation of the Lord.
Don't be too concerned about Karma. It is a complex concept which cannot be very easily explained.
Instead of bothering about sin or karma be concerned with what you have to do now. Whatever the present moment demands from you do that to the best of your ability in spite of whether you like it or not. Leave the result to the Lord.
This is not to suggest that you shouldn't desire or have any expectation of the outcome. Whether you desire/expect or not always accept the outcome as the Divine's blessing. Know that whatever you desire/expect it is the Divine that grants. So accept everything that is happening in your life as the grace of God. If you want to or desire to change something in your life work for it. If it is granted then it is the Grace. If it is not granted then too it is the Grace. Enjoy the happiness that you derive when your desire is fulfilled. Enjoy the unhappiness that you get when your desire is unfulfilled. This is Surrender.
Don't worry too much of sin or karma. Since you are the Lord (whether you agree to it or not you ARE the Lord) you cannot sin. Be happy.
Before you ask any more questions regarding sin or karma please read & re read this many times. You will have clarity.