If you make a list of all the things that you consider sin, in, let's say, any five major religions, then you will understand that to be alive is a sin!
So, if you don't feel guilty about something, you may not go to the temple or church or mosque? Fear and guilt have been two tools with which religion has been running for a long time. If there is no fear in people, there is no guilt in people and then very few would go to these places. Most of us go to such places because there is fear, guilt and greed.
We are used to follow certain ways of life that have made the fundamental processes of life as sinful; and that makes us feel always guilty. As a result, you see yourself always going to the temple or church or mosque and pay the necessary money and respect.
Do whatever you want, but understand that for every action that you undertake, there is a consequence. Every single action: whether physical, mental, emotional or whatever you perform, has a consequence. The only question is whether you are ready for the consequence.
If you can bear the consequence joyfully, do whatever you please. If you are the kind who will cry when the consequence comes, then you need to calibrate your actions. If you are the kind of person who thinks no matter what happens, even if you are going to be hanged tomorrow, you will still go blissfully.
There is no sin as such. So, does it mean everything is punniya? No. No 'papam', no 'punniyam.' It's all made up by people to keep you under check and control. Your sense is the best control, not guilt. I believe human intelligence is able to control itself. There is no need for some external force to control you. If you allow your intelligence to function, it will control you, and beautifully.
It will bring sense to your life. And you will live a happy and contented life.